Mr. Putman's 8th Grade Science Chapter 14

Which one of the following is NOT an example of work being done?

• the moon orbiting the Earth
• pushing a box from the bottom of a hill to the top of a hill
• pulling a sled across a field covered with snow
• lifting a bookbag off the floor

A fixed, single pulley that is used to lift a block does which one of the following?

• doubles the force required to lift the block
• decreases the force required to lift the block
• makes the block easier to lift by changing the direction of the force needed to lift it
• decreases the force required and changes the direction of the force required

A slanted surface used to raise an object is a(n)____.

• effeciency board
• effort ramp
• incline plane
• wedge

A device that does work with only one movement and changes the size or direction of a force is a(n) ___________.

• compound machine
• effort machine
• screw
• simple machine

A bar that is free to pivot about a fixed point is a ____.

• fulcrum
• lever
• ramp
• wedge

The rate at which work is done is called ____.

• efficiency 
• effort time
• force 
• power

The work output of a machine divided by the work input is the ____ of the machine.

• efficiency
• effort
• power
• resistance

The amount by which a machine multiplies an input force is called the ________.

• efficiency factor
• fulcrum
• mechanical advantage
• resistance force

An inclined plane with one or two sloping sides forms a machine called a ____.

• pulley 
• lever
• ramp 
• wedge

An inclined plane wrapped around a cylinder post is a ____.

• lever
• ramp
• screw
• wedge