Work+-+Energy+Problems

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 * Describe the difference between Kinetic Energy and Potential Energy. **


 * How does it relate to what we observed using the Xpult? **


 * Work is the force used to move an object some distance **


 * W = F x d **


 * Force needed to lift the box = 100 Newtons﻿﻿ **


 * Distance needed to lift the box = 2 meters **

it is 200 Joules
 * 1) What work was needed to move the box 2 meters? **
 * ( N•m is considered a Joule) **


 * Mechanical Advantage = Ouput force **
 * Input force **


 * 2) The board is 30 meters long. The fulcrum is 3 meters from the Boulder and 9 meters from the person applying the force. A person applies a force of 5 newtons and the boulder is 15 Newtons. **


 * What is the mechanical advantage? **

The MA is 15:5 or reduced it would be 3:1


 * What is the work being done by the Machine? **

15 N x 3 meters = 45 joules


 * What is the work being done by the person? **

5N x 9 meters = 45 joules


 * Compare the Work of the person and machine. **

The work of both the person and the machine both equal 45 joules. This is because the work is always the same for the person and the machine. What is different is the distribution of force and distance. The person exerts a small force over a large distance. The machine exerts a large force over a small distance


 * Explain scientifically why the job is easier for the person and harder for the machine. (even though the work is the same) **

see explanation above