PS.7.2.4 - Simple Machines

What is the fixed point around which a lever pivots called?

• Pulley

• Fulcrum

• Wedge

• Axle

Which simple machine consists of a rope that fits into a groove in a wheel?

• Lever

• Pulley

• Screw

• Wedge

What is the term for a device that makes work easier?

• Machine

• Efficiency

• Compound machine

• Inclined plane

Which of the following best describes a wedge?

• A bar that pivots at a fixed point

• An inclined plane that moves

• A rope in a groove

• Two attached circular objects

What is the mechanical advantage of a machine?

• The percentage of input work converted to output work

• The ratio of the output force to the input force

• The amount of work done by the machine

• The number of simple machines in a compound machine

Which simple machine is described as a slanted surface along which a force moves an object to a different elevation?

• Lever

• Pulley

• Inclined plane

• Screw

If you combine a wheel and axle with a pulley, what type of machine do you create?

• Simple machine

• Compound machine

• Lever

• Wedge

A screw is an example of which type of simple machine?

• A lever that pivots at a fulcrum

• An inclined plane wrapped around a cylinder

• Two wheels of different sizes

• A rope in a groove

If a machine has an efficiency of 80%, what does this mean?

• 80% of the input work is lost

• 80% of the input work is converted to output work

• The machine multiplies force by 80 times

• The machine is made of 80% simple machines

Which of the following is an example of a compound machine?

• A single lever

• A single pulley

• A pair of scissors (which uses levers and wedges)

• An inclined plane