1- Calculate the average velocity in(km/h) unit if a tracker cutting a distance. (4000m) in (30min.) ...... Mention the
Department : Physics
Cairo Governorate Nozha Directorate of Education Nozha Language Schools Ismailia Road
Form
:1st sec.
Revision Sheet 2014
Unit one Chapter one Definitions:
1- Measurement: it is a compare known quantity with unknown one to know how much is it.
2- Fundamental quantity: cannot be derived. 3- Derived quantity: can be derived from the basic quantities. 4- Standard meter The distance between two engraved marks at the ends of a rod made of platinum and iridium alloy kept at 0oC, at the international bureau of weights and measures near Paris. 5- Standard kilogram: Mass of cylinder made of Platinum and iridium alloy of specific dimensions kept at 0oC, at the international bureau of weights and measures near Paris. 6- Standard second: it is equivalent to
from the solar day.
International system unit (SI) Quantity Length Mass Time Current intensity Temperature Quantity of matter Light intensity Angle Solid angle
Symbol L M t I T n Iv
Direct measurement
Unit Meter (m) Kilogram (Kg) Second (s) Ampere (A) Kelvin (k) Mole (mol) Candela (cd) Radian Steradian
Indirect measurement
Use one step only. No mathematical substitution.
More than one step. Use mathematical relation to calculate the quantity. More than one error. Volume by length x width x height. Absolute error in ( + ) and ( - ) Δ x = Δx1 + Δ x2 Relative error in ( x ) and ( ÷ ) r = r1 + r2
Only one error can be. Measuring volume in graduated cylinder. Absolute error (Δx) = l xo – x l Relative error ( r ) =
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Chapter one Q1: what’s meant by: 1- Fundamental quantity. …………………………………………………………………………………… ……………………………………………………………………………… 2- Derived quantity: Standard meter? …………………………………………………………………………………… ……………………………………………………………………………… 3- Standard kilogram? …………………………………………………………………………………… ……………………………………………………………………………… 4- Standard second? …………………………………………………………………………………… ……………………………………………………………………………… 5- Measurement? …………………………………………………………………………………… ………………………………………………………………………………
Q2: write the scientific term: 1- It is the difference between the real quantity and the measured one. (…………………………………) 2- It happens when you make only one step. (………………...……………….) 3- It has more than one mistake. (………………………………….) 4- It is the ratio between the absolute error of the quantity and its real magnitude. (…….…..…………………....)
Q3: prove the dimensional formula for each of the following: 1- Density: ………………………………………………………………………………………………… 2- Force: …………………………………………………………………………………………………… 3- Area: ……………………………………………………………….………………….……………..… 4- Velocity: ……………………………………………………………………………………………….. 5- Acceleration:………………………………………………………………………..………………… Q2: Give reason for: 1- Force is a derived quantity? …………………………………………………………………………………… …………………………………………………….………………………… 2- We don’t use glass in standard units instead if platinum and iridium alloy? …………………………………………………………………………………… ………………………………………….…………………………………… 3- Scientists used atomic standard meter rather than the international standard meter? …………………………………………………………………………………… ………………………………..…………………………………………….. 2
4- It is impossible to measure quantity with 100% accuracy? …………………………………………………………………………………… ……………………………….…………………………………………….. 5- The relative error more accurate than the absolute error? …………………………………………………………………………………… ………………………………………………………………………………..
Q4: problems: 1- Find the relative and absolute error in measurement of cubes’ volume if the length = 5 cm when the student measure it, it was 5.2 cm. 2- Find the dimensional formula for volume? 3- If the force = mass x acceleration find its dimensional formula? 4- If the length of the wall of a room is 3.5 m, when you measure It, it was 3.6 m find the absolute and relative error for this measuring? 5- By adding two quantities q1 = (6.6 ± 0.2) and q2 = (5.9 ± 0.3) find the value of q? 6- In lab experiment to determine a physical quantity (L) by adding two physical quantities L1 & L2 if L1 = (5.2 ± 0.1) cm and L2 = (5.8 ± 0.2) cm, find L? 7- Calculate the relative error and absolute error when measuring the area of square L = (3.3 ± 0.3)? 8- Calculate the absolute and relative error of measuring area of rectangle L = (6.7 ± 0.6) cm and W = (5.5 ± 0.1) cm? 9- Calculate the relative error of measuring the length of the class room when the actual length is 6m and during measuring it was 6.4m? 10- Calculate the relative and absolute error for measuring a circle its radius = (2.2 ± 0.1) cm? 11- Calculate the (M) when subtract two quantities M1 = (7.3 ± 0.2) kg and M2 = (8.9 ± 0.1) kg?
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Unit one Vectors and scalars Definitions: Scalar quantity: that defined by its magnitude only. Vector quantity: that defined by its magnitude and direction. Distance: how much ground the object is covered. Displacement: the change of the position of an object. Or: straight line between the starting point and end point. 5- Resultant force: single force that results the same effect on the object as that produced by the original acting force.
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Note:
- Adding vectors if Ѳ = 90o A+B=C
A2 + B2 = C2
c =√ + ( )is the direction of the new vector which ┴ to the plane and can be got by (right hand rule)
- Product of vector: = AB cos Ѳ Scalar product: . = AB sin Ѳ Vector product = ^
- Resolution: F sinѲ F
F cosѲ
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Chapter two Q1: what is meant by: 1- The displacement of a body is 50 m. …………………………………………………………………………………… …………………………………………………………………….……….. 2- The distance covered by the body =10 m. ………………………………………………………………………………….… ………………………………………………………………………………
Q2: write the scientific term: 1- That defined by its magnitude only. (………….……………………) 2- Single force that results the same effect on the object as that produced by the original acting force. (………….…………………….) 3- The change in the position of an object. ( ……………………………….)
Q 3: give reason for: 1- Velocity is a vector quantity. ………………..…………………………………………………………………… ……………………………………………………………………………… 2- Distance is a scalar quantity. …………………………………………………………………………………… ……………………………………………………………………………
Q4: compare between distance and displacement. Q3: Problems: 3- Find the resultant of two forces; one of them (Fx = 4 N) acting in x- dimension, while the other (Fy = 3N) acting in y- dimension. 4- The magnitude of two vectors A and B are 5 and 10 respectively and the angle between them is 60o find the result of each of: 1- A. B 2- A ʌ B 5- Mohamed leaves the school and hikes 11 km, north and then hikes 11 km east. Determine Mohamed's resulting displacement. 6- A tines ball falls from a height of 20 m then rebounded to upward 4m, find its distance and displacement. 7- If the vector X is 3 and vector Y is 5 and these vectors making angle 60o between them find: a- Vector product with the direction. b- Scalar product. 8- A body moved in a circular motion of radius (r) find its displacement and distance when the body : a- Makes one complete cycle. b- Moves half cycle.
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Unit two Motion in straight line Motion: the change of the position of an object relative to a fixed point as time passes. Translational motion: the motion which has starting point and end point. Periodic motion: The motion that repeats itself in equal interval of time. Velocity: the rate of change of displacement. Or: the displacement of an object in one second. Acceleration: the rate of change of velocity. Or: The change of the object velocity per unit time. Translational motion The motion which has starting point and end point. Motion in straight line.
Periodic motion The motion that repeats itself in equal interval of time. Motion in circle.
Velocity The displacement of an object in one second. Vector quantity. Defined by its magnitude only
Speed The distance of an object in one second. Scalar quantity. Defined by magnitude and direction.
Uniform velocity At which the objects moves through equal displacements in equal interval of time.
Non uniform velocity At which the objects moves through unequal displacements in equal interval of time.
Displ. (m)
Displ. (m)
Time (s)
Time (s)
Positive acceleration. Zero acceleration. When the velocity increase. When the velocity is constant. Vel.(m/s
Vel.(m/s
Negative acceleration. When the velocity decrease. Vel.(m/s
Time (s)
Time (s)
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Time (s)
Chapter three Q1: Give reason for: 1- Fan motion is a periodic motion, while the train motion is a transitional motion. …………………………………………………………………………………… ………………………………………………………………………… 2- Average velocity may be equal to the instantaneous velocity. …………………………………………………………………………………… ……………………………………………………………………………… 3- When a body moves with constant velocity its acceleration = zero. …………………………………………………………………………………… ………………………………………………………………………………
Q2: Write the scientific term: 1- Distance moved by the object per unit time and scalar quantity. (……………..………………..) 2- Motion in which velocity changes with time. (………………………………) 3- At which the objects moves through equal displacements in equal interval of time.
(………………….…………………….)
Q3: What is meant by: 1- A car moves at uniform acceleration =-4 m/s2. …………………………………………………………………………………… ……………………………………………………………………………… 2- An object is displaced 20 m in 4 sec. …………………………………………………………………………………… …………………………………………………………………………… 3- The velocity of an object increases at a rate 4 m/s every 1 sec. …………………………………………………………………………………… ……………………………………………………………………………..
Q4: Problems: 1- Calculate the average velocity in(km/h) unit if a tracker cutting a distance (4000m) in (30min.) then calculate the distance cutting after (45min.) from the starting point with same velocity.
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2- The following graph represents a journey of a car: Vel.(m/s 15 10 5
Q
P
R 50
125
Time (s)
175
a- What is the maximum speed of the car? b- Describe the car motion during (PQ) c- Describe the car motion during (QR) d- In which point the brakes had been used (P, Q, and R). e- Calculate the total distance during this motion.
3- The table below illustrates the relation between velocity of an object and time: V (m/s)
5
10
20
30
A
40
T (s)
1
2
4
6
7
8
a- Plot the graph between vel. On vertical axis and time on horizontal axis: b- From the graph find: 1) The value of A. 2) The velocity of the object at the 5th sec. 3) The acceleration of motion and its type.
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Unit two Motion with uniform acceleration 1st equation of motion:
=
=
∆
V f = Vi + a t
a t =V
f
- Vi
----------------------------------------------------------------------------------2nd equation of motion:
=
∵ =
# + $ & = 2 '
"
2d = (Vf + Vi) t From 1st eq. (Vf = Vi + at)
d = Vi t + at2
2d = (Vi + at + Vi)t 2d = (2Vi + at)t
------------------------------------------------------------------------------------------------------3rd equation of motion:
=
∵ =
d = v av. t "
From 1st eq. ' = &=
# + $ # − $ ( 2
Vf2 = Vi2 + 2ad
2ad = (Vf + Vi) (Vf – Vi) 2ad = Vf2 – Vi2
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Projectile s: a) Upward: Vf = 0 , g= 10 m/s2, b) with angle:
h R
Vix = Vi cos θ
⇒
Viy = Vi sin θ
1- Vfy = Viy + (-gt) ⇒
Viy = gt
⇒ +=
Time of flight (T) = 2t =
0 = Viy – gt ,-.
/
0 ,-. /
(1)
2- Vfy2 = Viy2 + 2gh 0=
Viy2
+ 2gh ,
Viy = 2gh ⇒ h = 2
3- R = Vix 2t = Vix T (3)
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,0-.
0/
(2)
Chapter four Q1: Choose: 1- The dimensional formula of acceleration ………. a) LT-1
b) LT-2
c) L-1 T-2
d) L-2 T-2
2- When the change of velocity equal zero ,……… a) a is negative.
b) a is positive.
C) a = 0
d)body at rest.
3- If the direction of velocity and acceleration is negative …………….. a) Velocity increase.
b) Velocity decrease.
C) Velocity is constant.
d) body stopped.
4- Two different objects have the same volume falls together from the same height which of these statement is correct: a) The heavier reaches ground first b) the lighter reach first. c) acceleration of the heavier is bigger. d) reaches ground together.
Q2: what is meant by: 1- Displacement of a table is 3m? …………………………………………………………………………………… ………………………………………………………………………………. 2- Velocity of a bike = 5m/s? …………………………………………………………………………………… …………………………………………………..…………………………. 3- Acceleration of gravity = 9.8 m/s2? .................................................................................................................................. ..........................................................................................................................
Q3: Problems: 1- Person projected object from high building with velocity (50m/s) if the acceleration due to gravity is (10m/s2) calculate the velocity and the displacement moved by the object after (4s) in the following cases: a) If projected vertically upward. b) If projected vertically downward. c) If it projected with angle 30o with horizontal plane. d) If it projected with angle zero with the horizontal plane.
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2- A car moved in straight line and record its velocity during (30s) the following graph represents the car motion: Vel.(m/s B
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C D 30
A
Car motion Vi Vf ∆V t a Description of motion.
AB
Time (s)
BC
CD
3- A car was moving at 20 m/s. when the brakes were applied uniformly at 2m/s2 calculate: a) Time taken to stop. b) Distance moved during braking. c) The average velocity during this interval. 4- A driver saw the red traffic light when it was moving at 80km/h ,at 100m away from the car he used the brakes to decelerate at 2m/s2 a- Would the car cross the traffic sign? b- Calculate the time taken by the car to stop. 5- An object is projected vertically upwards at velocity 147m/s if the free fall acceleration is 9.8m/s2 find: a) The object velocity after 5s from the projection. b) The maximum height reached by the object. c) The total time taken by the object till it returns back. 6- A train driver applied the brakes when the train was moving at 20m/s to stop the train in a minute. Calculate the acceleration and the distance moved till stopped. 7- An object is projected upward with velocity 20m/s making angle with the horizontal plane 30o find: a- The horizontal component of its initial velocity. b- The vertical component of velocity at the first and at the maximum height. c- The flight time. d- The maximum height reached by the object. e- The distance between the starting and ending position.
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Unit two Force and motion Force: external influence that affects the object to change its state of motion or direction. Newton's law Newton's firs law:
Mathematical Definitions formula ΣF = 0 A static object keeps its state of rest, and a moving object keeps its state of motion at a uniform velocity in a straight line unless acted upon by a resultant force.
Newton's second law:
ΣF ≠ 0 F=mxa
When a resultant force acts on object, the object acquires an acceleration which is directly proportional to the resultant force and inversely proportional to the object mass.
Newton's third law:
F = -F
When an object acts on another object by a force, the second object reacts with an equal force on the first object in a direction opposite to that of action. Or: every action has reaction equal in magnitude and opposite in direction.
Mass The resistance of an object to change its dynamic state. Fundamental, scalar. 1
M= kg Constant at everywhere.
Notes Inertia: The tendency of an object to keeps either its state of rest or state of motion at its uniform velocity in straight line. OR: the resistance of object to change its static or dynamic state. Newton: it is the force that when acts on an object of mass 1kg accelerates it at 1m/s2. F=mxa N = kg. m /s2 Dimensional: M L T-2
Weight The force of gravity acting on a body. Derived, vector (to the center of the earth) W=mxa Newton Changed from position to another.
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Chapter five Q1: Choose: 1- When the resultant force acting on moving object is zero, the object…….. a- Stops motion. c- Moves at uniform velocity. b- Moves at non uniform velocity. d- Moves at uniform acceleration. 2- The mathematical formula that expresses Newton's third law …….. a- F1 =-F2 b- F = m x a c- ΣF ≠ 0 d- ΣF =0 3- A car moving with uniform velocity in straight line to east when the resultant force on the car …………….. a- Zero. b- -ve c- + ve d- to east. 4- When an abject projected vertically with vi with an angle 60o with the horizontal plane so it cover horizontal distance R, to reach distance farther than this starting with same velocity we have to project it with angle equal……….. a- 90o. b-75o. c- 45o. d- 30o. 5- The graph which represents motion of body with uniform velocity? X
a-
X t
b-
V t2
c-
V t
d-
t
Q2: Give reason for: 1- Passengers in the bus fall forward when it stops suddenly. …………………………………………………………………………………… ……………………………………………………………………………… 2- A space rocket does not need to consume more fuel after being moved away from the earth's gravity. …………………………………………………………………………………… ……………………………………………………………………………….. 3- The rotation of fan after turn off the current. …………………………………………………………………………………… ……………………………………………………………………………… 4- Force is a vector quantity. …………………………………………………………………………………… ……………………………………………………………………………… 5- The objects weigh on earth is greater than its mass. …………………………………………………………………………………… ……………………………………………………………………………… 6- No single force could exist in the universe. …………………………………………………………………………………… ……………………………………………………………………………..
Q3: if a train moves forward suddenly so what is the direction of the bag motion which lies below the chair?
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Q4: we can say that Newton's 1st law special case from Newton's 2nd law. Explain. Q5: Problems: 1- Calculate the acceleration by which the two loads move. Neglect friction force. if m1=5kg and m2=7kg. 2- A static object of mass 20kg is affected by a force 30N. find: a- The acceleration acquired by the object. b- The time taken by the object to move a distance of 75m. 3- A body of weight 240N was moving at velocity of 25m/s. two seconds later,its velocity becomes 40m/s. assuming that the free fall acceleration=10m/s2 find the force acting on the body. 4- A static body of weight 400N was acted upon by a force 200N. giving that the body moved for 3s. and the free fall acceleration=10m/s2, calculate: a- The final velocity after 3s. b- The distance covered in 3s. 3 5- Three masses are connected together by weightless threads as shown in fig. they are pulled on a smooth surface by a horizontal force. find: a- The common acceleration of these masses. b- The tension force in each thread.
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Unit three Laws of circular motion motion Definitions: Uniform circular motion: the motion of body in a circular path at a constant speed and changeable direction. Centripetal force: the force acting continuously in a direction normal to the motion of a body, changing its straight path into circular path. Centripetal acceleration: the acceleration by an object moving in a circular path due to a continuous change in the direction of its velocity. Periodic time: the time taken to make one complete revolution.
Types of centripetal force: 12345-
Tension force. Gravitational force. Friction force. Reaction force. Lifting force.
Prove the centripetal Force: ∆ ∆2
=
3
V
∆4 , ∆, = 5 67 = 67 =
V r
∆, ∆+
∆L A r
∆4 , ∆+ 5
,0 67 = 5
87 = 9 : 67 87 = 9 :
B
,0 5
Factors affecting on F c: Fcα m
F c α 1/r F c α v2
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Chapter six Q1: Write the scientific term: 1- The force of attraction between two large bodies. (………...………) 2- The force due to the resistance of a surface to the motion of a body. (…………………) 3- The acceleration due to the change in the direction of body in circular motion. (………..………) 4- The time taken by moving object to make one complete revolution. (…………………) Q2: give reason for: 1- Although the body moving in a circular path it doesn't go to the center of the circle. ……………………………………………………………………… ……………………………………………………………………… 2- When a car turns in a circular path, it conserves moving on the in circular path. ……………………………………………………………………… ……………………………………………………………………… Q3: when each of the following happened: 3-
Fc
= a c (centripetal force equal to the centripetal acceleration). ……………………………………………………………………… ……………………………………………………………………… 4- ac = V2 (centripetal acceleration and linear velocity) ……………………………………………………………………… ……………………………………………………………………… 5- Acceleration is zero in circular motion. ……………………………………………………………………… ……………………………………………………………………… Q4: Problems: 1- An object of mass 2kg. moves around a circle of radius 2m. with velocity 12m/s, calculate. a- Centripetal acceleration. b- Centripetal force. c- Linear acceleration. 2- A car of mass 905kg. Moves in a circular path of 3.25km, calculate its tangential velocity if the force required to conserve its rotational motion equals 2140N. 20
3- A car of mass 1000kg. Moves with uniform velocity 5m/s rotating around a curve of radius 50m. Calculate the central friction force to conserve its motion on the curve. 4- An object of mass 2kg. Is held at the end of a rope and rotate in a horizontal circular path of radius 1.5m. so, that it makes 3 revolutions in one second, calculate: a- The tangential velocity. b- The centripetal acceleration. c- The tension in the rope.
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Unit three Universal gravitation law. law. The general gravitational law:
A body in the universe attracts another body by a force which is directly proportional to the product of their masses, and inversely proportional to square the distance between them. ;=
3
G = 6.67x10-11 N.m2 kg-2 Dimensions of (G) = M-1 L3 T-2 The gravitational field: The space in which the gravitational forces appear. The gravitational field intensity: the gravitational force acting on a mass 1kg. ?=
@A
(r = R +h)
BC
Satellites The orbital velocity: The velocity that makes the satellite rotates around the earth in circular path at a constant distance from the earth's surface. =D
@A B
= m/s
Importance of satellite: 1234-
In communication. Astronomical satellite. Remote sensing satellite. Spying satellite.
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Chapter seven Q1: Choose: 1- The acceleration due to gravity …………….. a- Is universal constant. b- Change from point to another on the earth. c- Changes according to the seasons. d- Changing according to the distance between earth and sun. 2- The velocity required by a satellite to rotate around a planet depends on …………. a- Its mass only. b- Mass of planet. c- Mass of planet and the distance between them. d- A constant. Q2: what happened in the following? 1- The satellite velocity = zero. ……………………………………………………………………… ……………………………………………………………………… 2- There is no gravitational force between earth and satellite. ……………………………………………………………………… ……………………………………………………………………… 3- The mass of one object decreases to its half and the distance between the two objects is doubled. (to the attraction force) ……………………………………………………………………… ……………………………………………………………………… Q3: problems: 1- If the mass of mercury planet is 3.3x1023kg and its radius is 2.439x106m, calculate the weight of an object of mass 65kg on its surface. What is the weight of the same object on earth's surface (G=6.67x10-11N.m2/kg2, g=9.8m/s2) 2- A satellite rotates in a circular path at height 300km from earth's surface, find: a- Its orbital velocity. b- Its periodic time. c- Centripetal acceleration. (R=6400km, g9.8m/s2)
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3- At what height from earth's surface, a satellite must rotate so that its periodic time around earth equal the time required by the earth to make a full revolution about its axis, if you know that (day on earth =24hour, Me = 5.98x1024kg , G= 6.67x10-11Nm2/kg-2) 4- A planet of mass 5.924kg if the relation between the mass of an object (m) and the attraction force between it and the planet (F) is given in the table. F (N)
40
M (kg) 5
80
120
160
A
240
280
10
15
20
25
30
B
a- Draw a relation between (F) on y axis and (m) on x axis. b- From the graph find: 1- The value of (A) and (B) 2- The radius of planet.
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Unit four Work and energy Work: Force acting on object leads to move it a displacement. Rule: W = F .d Unit: joule = N.m. = Kg m2/s2. Dimensional formula: M L2 T-2 Joule: it is the work done by a force of one Newton to move an object through a displacement of one meter in the direction of the force. Energy: P.O.C Definition:
Kinetic energy The energy possessed by the object due to its motion. M.R: K.E = m v2 1- Mass of object. Factors: 2- Velocity of object. Joule Unit: Dimension: ML2T-2 Prove of K.E:
Vf 2 – Vi 2 = 2 a d Vf 2 = 2 a d d=
C
F. d =
1 .C
K.E =
= (
1
( #
>
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Potential energy The energy possessed by the object due to its position or state. P.E = m g h 1- Mass of object. 2- Height above surface. Joule ML2T-2
Chapter eight Q1: Write the scientific term: 1- Work done by a force 1N to move an object through a displacement of 1m in the direction of the force. (…………………………..) 2- The work done to move an object. (…………………………..) 3- The energy stored in the object due to its height. (………………………….)
Q2: Choose: 1- An object of kinetic energy 4J, if its velocity is doubled, its kinetic energy ………. a- 0.8J. b- 4J. c- 16J. d- 8J. 2- When the velocity of car is doubled, its kinetic energy…………… a- Decrease to its half. c- is doubled. b- Increases 4 times. d- is inclined by an obtuse angle. 3- The energy stored in a spring is ………………….. a- Kinetic energy. c- attraction energy. b- Potential energy. d- repulsion energy.
Q3: Give reason for: 1- Work is a scalar quantity. ……………………………………………………………………………… ………………………………………………………………………… 2- When a person moves horizontal while carrying bag he doesn't do a work. ……………………………………………………………………………… ………………………………………………………………………… 3- The potential energy of water at the top of water fall is higher than it at its bottom. ……………………………………………………………………………… …………………………………………………………………………
Q4: Problems: 1- Calculate the work done to push a baby car a distance 3.5m by a force 20N. 2- A force of 100 acts on an object and moves it a distance 2.5m. calculate the work by the force in the following cases: a- The force is normal to the direction of motion. b- Making angle of 60o with the direction of motion. c- The force with the direction of motion. 3- Find the kinetic energy of a car of mass 2000kg. Moves with velocity 60km/h. 4- Find the mass of a body at the earth's surface if you know that its potential energy at a point that lies at a distance 5m. From earth's surface is 980J. ( g=9.8m/s2)
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Unit four Law of conservation of energy Law of conservation of energy: Energy neither created nor destroyed but transform from form to another.
Prove of conservation of energy: Vf2 – Vi2 = 2 (-g) d Vf2 – Vi2 = - 2 g (hf – hi) Vf2 – Vi2 = - 2 g hf + 2 g hi
(x
>)
mVf2 - mVi2 = - m g hf + m g hi
mVf2 + m g hf = mVi2 + m g hi
K.E + P.E = K.E + P.E M.E = M.E Mechanical energy: sum of kinetic energy and potential energy. Law conservation of mechanical energy: sum of potential and kinetic energy along the path of the object is constant.
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Chapter nine Q1: Choose: 1- The mechanical energy of an object = …………….. a- The difference between kinetic and potential. b- The sum of potential and kinetic. c- The ratio between kinetic and potential. d- The product of kinetic and potential. 2- If a body is throw vertically upward, at maximum height its …….=zero. a- Force. b- Acceleration. c- Potential energy. d- Velocity.
Q2: a body of mass 4kg falls freely from height 20m to the ground. Knowing that the acceleration due to gravity 10m/s2 complete the following: Point. Displ. From staring point. (m) 1 0 2 …………… 3 ……………. 4 ………….
Potential energy. (J) …………… …………. 400 ………….
Velocity (m/s) ………… 5 …………… ………….
Kinetic energy. (J) …………. ………….. …………… 800
Mechanical energy. (J) …………. …………… ………… ……………
Q3: Problem: 1- A ball is thrown vertically upwards so that its velocity becomes 3m/s at height 4m find the work done to throw the ball if its mass is 0.5kg and g=10m/s2. 2- An object of mass 0.2kg is thrown vertically upwards with velocity 20m/s neglecting air resistance, calculate: a- The maximum height reached by the object. b- The velocity at a height 10m from a the earth's surface.(g=10m/s2). 3- The following table shows the relation between the potential energy (P.E) and height from the earth's surface (h): P.E (J) 16 32 48 64 80 H (m) 2 4 6 8 10 a- Draw a graph between P.E on Y-axis and h on X-axis. b- From the graph find: 1- The potential energy at height 7m. 2- The mass of the object if g=9.8m/s2.
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Unit five Internal energy and temperature 1- Heat: it is the energy that flows from hot body to the cooler body. Unit: Joule, calorie (1calorie = 4.18J) or (1calorie = 4.18N.m) 2- Internal energy: the sum of potential energy and kinetic energy of substance molecule. (U = K.E + P.E) 3- Temperature: it is a physical quantity indicating the state of the body in terms of its hotness or coldness. Or: it is the average kinetic energy of the body molecule. Thermometers 4- Thermometer s: a- Fahrenheit scale (oF): (32o – 212o) b- Celsius scale (oC): (0o – 100o) c- Kelvin scale (oK): (273o – 373o) Tk = 273 + Tc E
Tf = 32 + Tc F
Thermal equilibrium: It is the state when two bodies in physical contact have the same temperature. -----------------------------------------------------------------------------------------------
Chapter ten Q1: Choose: 1- If the internal energy of a body increases its temperature ……….. a- Decrease. b- Increase. c- Doesn’t change. 2- If the temp. Of body increase 10o in Celsius scale it will increase by ------------in Kelvin scale. a- 80o. b- 18o. c- 10o. 3- The fundamental unit of temp. In international system unit is ……. a- Celsius. b- Fahrenheit. c- Kelvin.
Q2: what is meant by? 1- Quantity of heat? 2- Temperature?
Q3: complete the following table: Celsius (Tc) 100 …………………… …………………
Fahrenheit (Tf) ……………… …………… …………………..
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Kelvin (Tk) ………………. 0 100
Q4: the following table shows the relation between the lengths of mercury column in a mercury thermometer of different temperatures. Temperature (Tc)
0
10 20
b
40 50
Length of mercury (cm)
3
4
6
7
5
a
a- Draw the graph between (Tc) on X-axis and L on Y-axis. b- From the graph find both (a) and (b).
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Chapter two Heat energy ∆ Q = m .c. ∆t = J Specific heat capacity of a substance: Definition: the quantity of heat needed to raise the temp. of 1kg of the substance by one Kelvin. Role:
c=
∆H
I. ∆J
= J/kg. k
Phenomena and application: 1- Bodies of living organisms resist the rapid change in temp. 2- Water is used in cooling systems in car. 3- At the shores in hot summer the land is heated more than the water. Heat capacity: capacity: Definition: it is the quantity of heat energy requires to inc. the temp. of the body by 1ok. Role: q =
∆H ∆J
= >. L = J/ k.
Note: The heat capacity is differs for different masses of the same material. Latent heat: heat: Latent heat of fusion (Lf): the quantity of heat needed to convert 1kg of substance from solid to liquid without changing in temp. (Q = m. Lf) Latent heat of vaporization (L v): the quantity of heat needed to convert 1kg of substance from liquid to vapor without changing in temp. (Q = m. L v)
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Chapter eleven Q1: Define each of the following: 1- Specific heat capacity. ……………………………………………………………………………… ………………………………………………………………………… 2- Heat capacity. ……………………………………………………………………………… ……………………………………………………………………….. 3- Latent heat of fusion. ……………………………………………………………………………… ……………………………………………………………………… 4- Latent heat of vaporization. ……………………………………………………………………………… …………………………………………………………………………
Q2: problems: 1- An insulated container made of aluminum has mass 20g and container 150g of water at temperature 20oc.a metal piece of mass 30g is heated up to temp.100oc then dropped into water. If the final temp. Of the mixture is 25oc. finding the specific heat of the metal given that the specific heat of water and aluminum are 4200j/kg. K and 900j/kg. K respectively. 2- Find the heat capacity of a metal piece of mass 0.7kg if the specific heat of this metal is 460j/kg. k. 3- Calculate the quantity of heated needed to convert 100g of ice into vapor at 100oc given that the latent heat of fusion of ice = 3.34x105J/kg, the specific heat of water 4200J/kg. K and latent heat of vaporization of water= 2.25x106J/kg. 4- A piece of copper of mass 400g is heated using a quantity of heat 4680J, its temperature increases from 20oc to 50oc, calculate the specific heat of copper. 5- Calculate the raise in temperature of a cube of aluminum of mass 100g if it's put in a hot medium and gains a quantity of heat 4500J, knowing that the specific heat of aluminum 900J/kg. K.
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Test (1) Question (1) : [A] Choose the correct answer : 1. Two bodies fall freely to ground , if the mass of the first object is twice the mass of the second object . the ratio M = ………… [ 1M2 -
2M - 1 : 1 - 2 : 1 ] 3
2. In positive acceleration , ………………. [ Vi > Vf - Vi ˂ Vf - Vi = Vf - Vf = 0 ] 3. All the following are scalar quantities , except …………. [ length - velocity -
mass - time ]
4. If X = YZ and dimensions of (X) = MLT-2 and of Z = ML° T° so dimension of Y = ……………. [ MLT - M° LT-2 - ML° T2 - M° LT ] [B] Compare between : 1. Distance and displacement . 2. Velocity and acceleration ( definition - dimensions - relation - graph ) [C] Two forces F1 = F2 act on an object . if their resultant has magnitude 20 N and makes on angle 45° to X-axis , find : 1. The magnitude of F1 and F2 . 2. Find the dot product of the two forces . Question (2) : [A] Give reason for : 1. The velocity of body that is projected vertically upwards decreases till it reaches zero . 2. Acceleration is a vector while speed is scalar . 3. The relative error is more accurate than absolute error .
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[B] When each of the following equal zero ? 1. Acceleration 2. Velocity . 3. Vector product of two vectors (A) = 5 , (B) = 10 [C] A car was moving at 20 m/s . when the brakes were applied , it decelerated uniformly at 2 m/s2 . till it stop calculate : 1. Time taken to stop . 2. Distance moved during braking . 3. The average velocity during this time . Question [3] : [A] Write the scientific term : 1. A single force that results in the same effect on the object as that produced by the original acting force . 2. the rate of change of velocity . 3. The ratio between the absolute error and the real value of the quantity . 4. Velocity of an object at a given instant . [B] Write the mathematical formula : X
V
X
t2
t
t
[C] The table below illustrates the relation between velocity of an object and time : V (m/s)
5
10
20
30
A
40
t (s)
1
2
4
6
7
8
Plot the graph between velocity on Y-axis and time on X-axis . from the graph find : 1. Value of A . 2. The acceleration of motion . 3. Mention its types . 36
Test (2) Question (1) : A) Write the scientific term : 1- The physical quantity that can be fully defined by both magnitude and direction . 2- Energy is neither created nor destroyed but it converts from one form to another . 3- For every action there is a reaction equal in magnitude and opposite in direction . 4- It is a physical quantity indicating the state of the body in terms of its hotness or coldness . B) What are the factors that affect each of the following : 1- The centripetal force ( two only ) . of a satellite .
2- The orbital velocity
C) A body of mass ( 600 kg ) is pulled horizontally by a force of ( 200 N ) . If the line of action of the force makes an angle (60°) to the direction of displacement . find the work done by the force to displace this body through (5m) .
Question (2) : A) What is meant by : 1- Latent heat of fusion of ice = 334 kj / kg . 2- The velocity of an object increases at the rate 6 m/sec. every 1sec. 3- Internal energy . B) Two small balls of masses (4 kg ) and ( 2.5 kg ) are separated by a distance ( 2m ) between their centers . Calculate the mutual attraction force between them . ( given thar G = 6.67 × 10-11 N.m2 / kg2 ) C) The given graphs represent the state of motion of an object : Mention the graph which represents : 1- A body at rest . 2- A body is projected upwards . V
V
X
V
V0
(1)
(2)
(3)
t
t 37
(4) t t
Question (3) : A) Choose the correct answer : 1- If the temperature of a body increases 10° in celsius scale , it will increase by ……………. in Kelvin scale . a) 10° b) 32° c) 18° d) 80° 2- The alloy used up to make the standard kilogram is ……………….. a) gold and copper b) platinum and iridium c) cesium and argon
d) no correct answer
3- If the acting force on a body is doubled and its mass is decreased to half , the acceleration of its motion becomes ……………..
a) 1M4 a b) 1M2 a c) 2 a 4- The measuring unit of the heat energy is ……………. a) Calorie
b) newton
c) mole
d) 4 a d) candela
B) Compare between : 1- Kinetic energy and potential energy . ( two points of comparison at least ) C) A box fell from a helicopter plane that was staying still at 78.4 m high above the sea level. (giving that acceleration due to gravity is 9.8 m/sec2and neglecting the air resistance)
Find : 1- The velocity by which the box hit the water . 2- The time it took till splash . Question (4) : A) Give reason for : 1- The space rocket does not need to consume fuel after being moved away from the Earth's gravity . 2- Water is used in cooling system of nuctear reactors and cars . 3- Displacement is a vector quantity . b) Mention the dimensional formula of : 1- Density 2- Energy C) A centripetal force of 800 N affects on an object of mass 20 kg. to conserve its motion in a circular path of radius 10 m. calculate : 1- The object's velocity .
2- The centripetal acceleration
Question (5) : A) Define : 1- Specific heat capacity of a substance . 2- Joule B) Proof that :
V = D
