Post on 28-Mar-2015
transcript
Work and Machines
An investigation…
Work and Machines• Purpose: To examine the
mechanisms of simple machines and the effect they have on work. (AKS 15)
• Answer the following previewing questions:– What does it mean to do work?– What is a machine?– What are some examples of
machines?– How are machines helpful
when doing work?
Work and Machines• Challenge 1:
– Sketch and label as many parts of the wheelbarrow as you can. Be as detailed and specific as possible!
– Using a different color add the following words to your labels. DO NOT change any of the words you have already written!
Inclined plane
Wedge
Pulley
Wheel and axle
Lever
Screw
Work and Machines• Challenge 1:
– Draw and label the six simple machines found in your basket.
– HINT: Be creative about how you use your materials!
Inclined plane
Wedge
Pulley
Wheel and axle
Lever
Screw
Work and Machines• A machine is a device that
helps make work easier.• What does it mean to do
work?– Work occurs when:
• An object moves when force is applied.
• The direction of motion is the same as the direction of force.
– See p. 189 for examples.– So… work is when a force
causes an object to move in the direction of the force.
Work and Machines• Copy and complete the
following table.Machine 2 Characteristics 2
Examples1 Illustration
Work and Machines• Levers
Work and Machines• Inclined Plane
Work and Machines• Wedges
Work and Machines• Wheel and axle
Work and Machines• Pulleys
Work and Machines• Machines
– What do all of these machines have in common?• They all make work easier by
changing the size and/or direction of a force.
– What do you end up with if you combine 2 or more simple machines?
Work and Machines• Compound Machines
– A compound machine is made of 2 or more simple machines.• Are scissors simple or
compound machines?• How many simple machines
can you identify in this pair of scissors? Lever
WedgeFulcrum
Work and Machines• Compound Machines
– Challenge 6: Design a compound machine that uses all 6 simple machines. • Be sure to label the simple
machines you use!– www.edheads.org
Work and Machines