Work and Machines Lesson

Simple Machines

by William Lovering

​Simple Machines

How machines can and cannot make work easier​

Machines can...

• ​increase input force (but must decrease input distance)

• ​increase input distance (but must decrease input force)

• ​change the direction of force

​

​Machines cannot...

• ​Make you do less work

• ​Make you use less energy

Multiple Choice

Simple Machines help you do less work

• True

• False

Multiple Choice

Simple machines can reduce the amount of force you need to do work.

• True

• False

Multiple Choice

You can lift a 50 newton rock 2 meters with a force of 50 newton. How much work is this?

• 50 j

• 100 j

• 25 j

Multiple Choice

If I build a simple machine that will let me lift that 50 n rock 2 m, but I will only need to use 10 n of force, how much work would I need to do to the machine to lift the rock?

• 20 j

• 100 j

• 50 j

• 25 j

Multiple Choice

How much distance would I have to put in the machine to lift a 50 n rock 2 m if I put 10 n of force into the machine?

• 10 m

• 5 m

• 25 m

• 2 m

Multiple Choice

If a machine increases your force, it must decrease your distance.

• True

• False

Fill in the Blanks

There are

classes or types of levers.

Multiple Choice

Which of the following is NOT part of a lever?

• Effort Arm

• Base

• R

• Fulcrum

Multiple Choice

3. Which type of lever is this?

• First Class Lever
• Second Class Lever
• Third Class Lever

Multiple Choice

6. What kind of lever is this?

• First Class Lever
• Second Class Lever
• Third Class Lever

Multiple Choice

A wheelbarrow is an example of a:

• 1st class lever
• 2nd class lever
• 3rd class lever

Multiple Choice

• 1st Class
• 2nd Class
• 3rd Class
• It is not a lever

Multiple Choice

The nutcracker is the example of .......................

• First Class of lever

• Second Class of lever

• Third Class of lever

• Fourth Class of lever

Multiple Choice

What is definition of the effort?

• The fixed point or pivot
• The point where the force is applied 
• The point where the weight/resistance is coming from