Unit 5 General Physics Projectile Motion Practice Problems ... (answers: part c: -
9.8 m/s2; part d: 3 seconds; part e: vx = 15 m/s, vy = -29.4 m/s; part f: v = 33 m/s., ...
Unit 5 General Physics Projectile Motion Practice Problems WORKSHEET 1: Type 1 Projectile Motion: Objects launched horizontally (Neglecting air resistance)
Useful equations In the x direction
In the y direction
No acceleration in the x direction ǻx = xf = xi + vx(t) however, xi = 0 so, ǻx = xf = vx(t)
Where a = g, the acceler. due to gravity ǻy = yf = yi + viy(t) + ½ a(t2) however, yi = 0 and viy = 0 so, ǻy = yf = ½ a(t2)
vix =
vfy = viy + a(t) but viy = 0 so, vfy = a(t)
vx = constant
…………………………………………………….. Example Problem: Casey throws a stone horizontally at 15 m/s from a top of a cliff that is 44 m high as shown. a) Draw a parabola to show its motion. b) Include vx and vy velocity vectors at several locations along the parabola. c) What is the acceleration vector along the parabola d) How long (t) will it take the stone to strike the ground? e) What are the velocity vector components (vx and vy) just before it strikes the ground? f) What is the overall velocity vector (magnitude and angle) just before it strikes the ground? g) How far did the rock travel horizontally (xf) before it hit the ground?
(answers: part c: -9.8 m/s2; part d: 3 seconds; part e: vx = 15 m/s, vy = -29.4 m/s; part f: v = 33 m/s., ș = -63°; part g: 45 meters)
Problem 1: Ryan rolls a steel ball horizontally at 0.8 m/s from a top of a lab table that is 0.95 m high as shown. a) Draw a parabola to show its motion. b) Include vx and vy velocity vectors at several locations along the parabola. c) What is the acceleration vector along the parabola (answer: -9.8 m/s2) d) How long (t) will it take the stone to strike the ground? (answer: 0.44 sec) e) What are the velocity vector components (vx and vy) just before it strikes the ground? (answers: vx = 0.8 m/s; vy = -4.3 m/s)
f) What is the overall velocity vector (magnitude and angle) just before it strikes the ground? (v = 4.37 m/s, ș = -79.5°)
g) How far did the rock travel horizontally (xf) before it hit the ground? (answer: 0.35 m)
Problem 2: An airplane is in level flight at a velocity of 138 m/s and at an altitude of 1500 meters when one of its wheels falls off. a) How long does it take the wheel to reach the ground? (answer = 17.5 sec) b) What horizontal distance will the wheel travel before it strikes the ground? (answer = 2415 m) c) What will the wheel’s velocity vector (overall velocity vector, magnitude and angle) just before it strikes the ground? (answers: v = 220.1 m/s, ș = -51º)
Problem 3: A rifle with a muzzle velocity of 200 m/s is fired with its barrel held into place horizontally. The bullet strikes the ground 112 meters away. How high is the gun being held above the ground? (answer = 1.54 m)
