ChemPhys 173/273

Unit 11: Work, Energy and Power

Problem Set A

 

Overview:

Problem Set A targets your ability to use equations related to work and power in order to solve 1-, 2- and 3-step problems. There are three equations of importance in the completion of this set.

 

 

To be successful on this problem set, you will have to master the use of the above equations. Additionally, you will need to be able to:

 

One Final Caution:

This problem set only test your conceptual understandings in addition to you mathematical abilities. It is common in many of the problems that extraneous numerical values will be stated in the problem description; such values do not need to be used in the solution. This extraneous information will be a distraction primarily to students who treat physics problems as mere exercises in mathematics. Without an understanding of the above relationships, you will be tempted to force such information into your calculations. Physics is about conceptual ideas and relationships; and problem sets test your conceptual understanding of these relationships. If you treat this problem set as a mere exercise in the algebraic manipulation of physics equations, then you are likely to become frustrated quickly. As you proceed through this problem set, be concepts-minded. Do not strip physics of its conceptual meaning.

 

 Additional Readings/Study Aids:

The following pages from The Physics Classroom tutorial may serve to be useful in assisting you in the understanding of the concepts and mathematics associated with these problems.

Work | Sample Work Calculations | Power

Resolving Fgrav on an Inclined Plane

 

 

View Sample Problem Set.

 

Problem

Description

Audio Link
1

Calculation of the work done from force and displacement.

2

Calculation of the displacement of an object from the work and the force.

3

Calculation of the work done upon an object moving vertically at a constant speed.

4

Calculation of the work done upon an object by a force exerted at an angle to its displacement.

5

Calculation of the work done upon an object when pulled up an inclined plane at a constant speed.

6

Calculation of the work done on a squirrel doing push-ups; must consider the total number of push-ups.

7

Calculation of the power output of a person running up stairs in a stated amount of time.

8

Calculation of the power of an escalator at a shopping mall.

9

Use of the P = F•v equation to determine the maximum speed of an elevator when the motor operates at maximum capacity.

10

Use of the P = F•v equation to determine the maximum speed of an skiiers on a toe rope when the motor operates at maximum capacity.

11

Determination of the work done by friction upon a sliding baserunner.

12

Determination of the work done by friction upon an object moving at a constant speed.

13

Calculation of the work done upon an object by a force exerted at an angle to its displacement.

14

Calculation of a the power output of a car if given mass, intial and final speed, and time information.

15

Calculation of a the power output of an elevator motor if given mass, intial and final speed, and time information.

Return to: Set A Overview Page || Audio Help Home Page || Set A Sample Problems

Audio Help for Problem: 1 || 2 || 3 || 4 || 5 || 6 || 7 || 8 || 9 || 10 || 11 || 12 || 13 || 14 || 15 ||

Retrieve info about: Problem-Solving || Audio Help || Technical Requirements || CD-ROM

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