Simple Machines Lessons

Multiple Choice

You push down on a lever with a force of 100 N to lift a 500 N box.

What is the input force?

• 100 N

• 500 N

Fill in the Blanks

You push down on a lever with a force of 100 N to lift a 500 N box.

What is the mechanical advantage of the lever?

Fill in the Blanks

As a percent, what is the efficiency of a machine that puts out 90 J of work when you put in 100 J of work?

Multiple Choice

A wheelbarrow is a good example of what class of lever?

• first class

• second class

• third class

Multiple Choice

A human arm is a good example of what class of lever?

• first class

• second class

• third class

Multiple Choice

Which of these items is a first class lever?

• scissors

• fishing rod

• tweezers

• none of these

Multiple Choice

A wedge has an output force of 25 N when given an input force of 5 N. What's the wedge's mechanical advantage?

• 0.2

• 5

• 20

• 30

Multiple Choice

A simple machine has an input force of 12 N and an output force of 4 N. What is its mechanical advantage?

• .33

• 3

• 8

• 16

Multiple Choice

The 3 parts of a lever are:

• fulcrum, effort, and load

• load, output, and input

• input, effort, and fulcrum

• pivot, output, and fulcrum

Multiple Choice

The IMA (ideal mechanical advantage) formula of a lever is:

• output/input

• input/output

• length of input arm/length of output arm

• resistance arm length/effort arm length

Multiple Choice

What is the ideal mechanical advantage of an inclined plane which has 4 cm height and length of 16 cm?

• 1/4
• 1
• 16
• 4

Multiple Choice

What is the Mechanical Advantage of an inclined plane with a height of 36 inches and a length of 72 inches?

• 2

• 4

• .5

• 1/2

Multiple Choice

If the weight of the block is 10N, how much force does one have to apply to lift it using this pulley (MA=2)?

• 2N
• 5N
• 10N
• 15N

Multiple Choice

A box of weight W is lifted by a force F using a lever as shown below.

What is the mechanical advantage of the lever (MA=Input Distance/Output Distance)?

• 0.5

• 2

• 3

• 6

Multiple Choice

Using a lever, Joe is able to lift a 10,000 N car off of the ground with a force of 1000 N. What is the mechanical advantage of the lever (MA=Output Force/Input Force)?

• 1

• 10

• 100

• 1000

Multiple Choice

if a load of a lever is 100 newtons and the force you apply is 20 newtons, what is your mechanical advantage?

• 120 N
• 5 N
• 2000 N
• 80 N