Physical Science chapter 13

lift a heavy box for 5 seconds and can’t make it budge, the work done on the box is__than zero

• equal to

• more than

• less than

Machines _____ the amount of energy that is needed to do work.

• increase

• equalize

• decrease

What is the mechanical advantage of a ramp that is 10 meters long and 2 meters high?

• 5

• 8

• 20

• 15

Because of friction, using machines __the amount of energy to do work.

• decrease

• equal

• increase

• neutralize

multiple pulleys causes the direction of the output force to be __the direction of the input.

• backwards

• opposite

• in

• forwards

A first class lever can have an input force ___ the output force.

• less than

• in the direction of

• equal to

• greater than

A second class lever always had an input force that is ___ the output force.

• in the same direction as

• equal to

• greater to

• less than

A wheelbarrow is an example of a

• first class lever

• second class lever

• third class lever

• fourth class lever

Which of the following is an example of a third class lever?

• nutcracker

• screw

• crow bar

• hand held boar paddle

What is the mechanical advantage of a single movable pulley?

• 1

• 1.5

• 2

• 3