Work and Power Test Review

Thurs May 23

Formulas: Take these down since they will not be on the test.

Formulas: Take these down since they will not be on the test.

Formulas: Take these down since they will not be on the test.

Formulas: Take these down since they will not be on the test.

Units: If you do a problem and don’t include the units in an answer you get no crecit

• Work= Joules• Power = Watts• KE= Joules• PE = Joules• F= Newtons• M= kg• D= m

Format of Test

a)10 True and Falseb)24 Multiple choicec)5 Math problems

Question 1

• As the mass increases the kinetic energy increases.

Question 2

• All forms of energy are just the same thing.

Question 3

• Energy is measured in joules.

Question 4

• In a car engine burning fuel produces heat.

Question 5

• Light energy travels from the sun and is transformed to chemical energy by plants.

Question 6

• On a swing the kinetic energy is the greatest at the lowest point.

Question 7

• Energy doesn’t necessarily involve motion.

Question 8

• Energy is the ability to do work.• Energy is the ability to cause

change.

Question 9

• Raising an object increases its potential energy.

Question 10

• Work is done when an object is moved and the force that causes the motion is in the same direction as the movement.

Question 11

• A power problem.

Question 12

• Kinetic energy = the energy of motion.

Question 13

• During nuclear reactions mass is converted to energy.

Question 14

• A kinetic energy problem.

Question 15

• The formula for work is W=Fd or Work= force x distance.

Question 16

• Joules are the units for work

Question 17

• Gravitational potential energy is the energy of an object due to its position.

Question 18

• If you double the velocity of an object its kinetic energy is quadrupled since the formula involves the square of the velocity. The square of two is four.

Question 19

• Power is the rate at which work is done.

Question 20

• Law of conservation of energy.

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Question 21

questio

• Definiton of power.

Question 22

• A work problem.

Question 23

• When you wind a watch you are working with a spring inside the watch which involves elastic potential energy.

Question 24

• Definition of power.

Question 25

• A power problem.

Question 26

• Calculate the work done in a situation

Question 27

• The kinetic energy of an object increases as its velocity increases.

Question 28

• Mechanical energy is the sum of the kinetic and potential energy of an object.

Question 29

• A vehicle converts the chemical energy of the fuel into kinetic energy.

Question 30

• A work problem.

Question 31

• A kinetic energy problem. Remember the potential energy at the top equals the kinetic energy at the bottom.

Question 32

• Find the object in a list that does not use electric energy

Question 33

• Watts are the units of power.

Question 34

• Definition of elastic potential energy.

Bubba picks up a 250 kg sack of grain and puts it on his shoulder 1.2 m above the ground. What is the potential energy of the grain?Given Work Answer

M=250 kgH=1.2G= 9.8

W=PEPE=mghPE= 250 (9.8) 1.2

2940 J

A 90-kg male gymnast does the iron cross 4.5 m above the floor. Find his potential energy. Given Work Answer

M=90 kgH=4.5G= 9.8

W=PEPE=mghPE= 90 (9.8) 4.5

3969 J

A 10-kg bicycle carrying a 90-kg guy is traveling at a speed of 7 m/s. What is the kinetic energy of the guy and the bicycle?

Given Work Answer

A ball weighs 7.6 N and can be kicked a distance of 1.5 m. What is the work applied to the soccer ball? Given Work Answer

F= 7.6D= 1.5

W=FdW= 7.6 (1.5)

11.4 J

How much work is applied to your backpack if 100 W of power are used for 25 seconds? Given Work Answer

P= 100 WT= 25 s

P=W/tW=PtW= 2500

2500 J