Advancing with Simple and Powered Machines Learning Grid ... LEGO and the
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education Advancing with Simple and Powered Machines Learning Grid 2009687 o 111oUl i s
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3I Science Collection, summary, and display of evidence Recognize the relationship between explanation and evidence Organize and communicate scientific findings Identifying variables Forces acting on the objects Equilibrium
Technology Technological and scientific knowledge Apply design process Test and evaluate Model a solution to a problem Identify criteria and constraints Evaluate design Use collected data to find trends Identify trends Interpret and evaluate accuracy of information Subsystems of transportation system Purpose of structures Engineering Identify, explain, and apply the steps of the engineering design process Demonstrate methods of representing solutions to a design problem Describe and explain the purpose of a given prototype Explain the forces of tension and compression Explain design feature Maths Understand both metric and customary systems of measurement Us* formulas Examine patterns and trends Construct and evaluate mathematical arguments Formulate explanations Recognize and apply mathematics in contexts outside of mathematics Create and use representations to organize, record, and communicate mathematical ideas Use representations to model and interpret physical, social, and mathematical phenomena
LEGO and the LEGO logo are trademarks of the/sont des marques de commerce de/son marcas registradas de LEGO Group ©2009 The LEGO Group.
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Student Worksheet
Simple Machines: Lever The lever is probably the most commonly used simple machine. A lever is a rigid bar or solid object that is used to transfer force. With a fulcrum, the lever can be used to change the force that is applied (effort), alter the direction, and change the distance of movement. Effort, a fulcrum and a load are three features that are common in every lever. Depending on the positions of these shared features, you can distinguish between first, second or third class levers.
4
1
oad
Effort
Fulcrum
First class levers have the fulcrum positioned between the effort and the load. Common examples of first class levers include a seesaw, a crowbar, pliers, and scissors.
Load
Effort
Fulcrum
Second class levers have the fulcrum and the effort at opposite ends and the load positioned between the two. Common examples of second class levers include nut crackers, wheel barrows, and bottle openers.
Effort
Load
Fulcrum
Third class levers have the fulcrum and the load at opposite ends and the effort positioned between the two. Common examples of third class levers include tweezers and ice tongs.
LEGO and the LEGO logo are trademarks of the/sont des marques de commerce de/son marcas reglstradas de LEGO Group. ©2009 The LEGO Group.
Did you know? The term lever derives from the French word levier which means to raise:
Student Worksheet
Simple Machines: Lever
The mechanical advantage of a lever The mechanical advantage of a lever is the ratio of the length of the effort arm to the length of the load arm. It can be calculated using the following formula:
Mechanical advantage =
Length of effort arm Lenght of load arm
Effort
Load
The mechanical advantage of this 1st class lever is:
Mechanical advantage = Mechanical advantage =
2m 0.5m 4
The amount of effort needed to lift a given load with any class of lever can be calculated using this formula:
Effort force x length of effort arm = Load force x length of load arm
90*
Effort x 2 m = 400 N x 0.4 m 400 N x 0.4 m Effort = 2m
Effort =
80 N
Using this 1st lass lever to lift a 400 N load would only need an effort of 80 N. However, the effort end of the lever must move five times the distance of the load.
LE3O and the LEGO logo are trademarks of the/sont des marques de commerce de/son marcas registradas de LEGO Group. S2009 The LEGO Group.
Simple Machines: Lever
A1 Build A1 book I, pages 2 to 3 Calculate the mechanical advantage of this lever. Then define the class of lever.
A2 Build A2 book I, pages 4 to 5 Calculate the mechanical advantage of this lever. Then define the class of lever.
A3 Build A3 book I, pages 6 to 7 Calculate the mechanical advantage of this lever. Then define the class of lever.
LEGO and the LEQO logo are trademarks of the/sont des marques de commerce de/son marcas regtstradas de LEGO Group. ©2009 The LEGO Group.
Student Worksheet
