chapter 9

Question 1

potential energy is associated with…

Answer 1

position

Question 2

kinetic energy is associated with….

Answer 2

motion

Question 3

what is energy measured in

Answer 3

Joules

Question 4

What is Work

Answer 4

a process that changes the energy of a system by mechanical means, pushing or pulling

Question 5

what’s the energy principle

Answer 5

energy cannot be created or destroyed,

Question 6

What is power

Answer 6

the rate at which energy is transferred or transformed

Question 7

symbol for kinetic energy

Answer 7

K

Question 8

Symbol for potential energy

Answer 8

U

Question 9

whats the environement

Answer 9

objects external to the system but exerting forces on the system

Question 10

whats the system

Answer 10

objects whose motion and environment we wish to analyze

Question 11

law of conservation of energy

Answer 11

As long as the system is not interacting with the environment, the total energy of the system is unchanged.

Question 12

interactions with environment

Answer 12

can transfer energy in and out of the system

Question 13

Two ways to transfer energy

Answer 13

through work (pushing or pulling using forces) or thermal means

Question 14

energy principle formula

Answer 14

(triangle)Esys= Wext

Question 15

energy is transformed within the system without

Answer 15

loss

Question 16

energy is transferred to and from the system by

Answer 16

forces of the environment

Question 17

The energy of an isolated system—one that doesn’t interact with its environment—does not change. We say it is

Answer 17

conserved

Question 18

draw a before and after representation of a particle of mass m acted on by a constant force acting parrallel

Answer 18

nice pic

Question 19

kinetic energy equation

Answer 19

K=1/2mv^2

Question 20

if kinetic energy is negative the particle….and if its positive….

Answer 20

slows down, speeds up

Question 21

all forms of energy are measured in

Answer 21

Joules (J)

Question 22

whats the kinetic energy of a .5kg mass moving at 4m/s

Answer 22

4J

Question 23

A 1000 kg car has a speed of 20 m/s. A 2000 kg truck has a speed of 10 m/s. Which has more kinetic energy?

Answer 23

the car

Question 24

tell me every part of this equation: (triangle)K=Kf-Ki=W

Answer 24

change is sutems kinetic energy=final kinetic energy - inital kinetic energy (aka amount of work done by external force)

Question 25

A 5.0 kg cannonball is fired straight up at 35 m/s. What is its speed after rising 45 m?

Answer 25

18m/s

Question 26

If the force causes the particle to speed up, then the work done by that force is

Answer 26

positive

Question 27

negative work means that the force is causing the object to

Answer 27

slow and lose energy

Question 28

work is positive when the force acts in the direction of the

Answer 28

displacement

Question 29

work is negative when force and displacement are

Answer 29

in opposite directions

Question 30

When work = 0, the particle

Answer 30

does’nt move

Question 31

A rock falls to the bottom of a deep canyon. Is the work done on the rock by gravity positive, negative, or zero

Answer 31

positive, displacement and gravity both downwards

Question 32

A force perpendicular to the displacement does

Answer 32

no work

Question 33

Two equal-mass pucks on frictionless ice are pushed toward each other by two equal but opposite forces. Is the total work positive, negative, or zero?

Answer 33

zero