Simple machines 1

True or False. The formula for work is Work = Force x Distance (W= F x D).

• True

• False

The unit of measure for work is_____________.

• meters

• joules

• newtons

• millibars

The unit of measure for force is _____________

• meters

• joules

• miles per hour

• newtons

A simple machine is a device that helps to reduce the amount of _____ required to work.

• force
• energy
• work

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?

• 1
• 10
• 100
• 1000

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

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

• output/input

• input/output

• distance of effort/ distance of load

• resistance arm length/effort arm length

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

What is the efficiency of a machine if 55.3 J of work are done on the machine, but only 14.3 J is produced by the 1machine?

• 0.25 J
• 26%
• 386%
• 3.86 J

What is the efficiency of the machine if the input is 263 J and the output is 142 J? 

• 6.26%
• 54%
• 100%
• 260%