POE Simple Machines, Mechanical Advantage and Work

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

Jeff is a landscaping contractor and lifts a rock weighing 600 pounds by wedging a board under the rock. Jeff weighs 150 pounds and puts all of his weight on the lever. How much mechanical advantage did the lever provide to Jeff in lifting the rock?

• 0
• 2
• 4
• 8

A lever and fulcrum are used to lift a fallen tree, which has a weight of 480 N. If the lever has a mechanical advantage of 5.5, what is the input force that will begin lifting the tree off the ground?

• 5.5 N
• 40.7 N
• 87.3 N
• 2640 N

The units for MA are called

• Joules
• Watts
• newtons
• MA is a ratio so it does not have units

What is the equation for work

• W = F x D
• F = M x A
• y = mx + b
• 25 eevee eggs equals one evolution

What is the equation for Mechanical Advantage?

• MA=resistance distance/effort distance

• MA=effort force/resistance force

• MA=resistance force/effort force

• MA= effort distance/resistance distance

What is the Mechanical Advantage if you lift a load of 300 newtons and you only push down with 50 newtons?

• 250
• 60
• 50
• 6

Machines don't reduce energy you need to move things, but they reduce what?

• Weight
• Mass
• Force
• Height

What is effort (input) force?

• the force one exerts on a machine

• the force which an effort force must overcome in order to do work on an object via a simple machine.

• the force the machine exerts on a object

• the output work times the input distance

What is resistance (output) force?

• the force required by a machine in order to accomplish work (the force you put on the machine)

• The force that is exerted by a machine

• the force the machine exerts on a object

• the output work times the input distance