Simple Machines

A machine is a device that____________.

• changes either the magnitude or direction of force
• always makes lifting objects require more effort
• changes only magnitude of the force
• Changes only direction of the force

Which of the following listed is a simple machine?

• A car
• An inclined plane
• A bicycle
• A chair

Which 2 simple machines are modified versions of an inclined plane?

• wedge and screw
• lever and pulley
• wheel and axle
• wedge and pulley

True or False: No machine is 100 % efficient.

• True
• False

What is considered to be the work input?

• Work that goes into or exerted on a machine
• work that comes out of or results from a machine

What is the equation for efficiency?

• Work Output/Work Input
• Work Input / Work Output
• mass * Work
• Work Input * Work Output

What is the definition for mechanical advantage?

• the number of times a machine increases the input force
• the number of times a person can lift a weight
• how much work is done in a given amount of time
• the rate of doing work

What is the equation for Ideal Mechanical Advantage?

• Input distance/output distance
• Output force/input force

What is the equation for Actual Mechanical Advantage?

• input distance/output distance
• output force/input force

What is the idea mechanical advantage if you push down a lever 10 m from the fulcrum and the load is 2 m from the fulcrum?

• 5
• 10
• 2
• 1