chapter 10

Question 1

what is total energy

Answer 1

it is the sum of energies in a system

Question 2

what type of quantity of energy

Answer 2

it is a scaler, not a vector

Question 3

what is a property of energy and its conservation?

Answer 3

energy of one kind can be transformed into energy of another kind within a system

Question 4

how is energy transferred between the system and environment

Answer 4

it is transferred through heat and work

Question 5

what is work

Answer 5

work is the transfer of energy to or from a system by pushing or pulling on it (due to a external force)

Question 6

what is heat

Answer 6

heat is the nonmechanical transfer of energy between a system and the environment due to a temperature difference (cause by temperature differences or friction)

Question 7

what is a change in energy caused by?

Answer 7

it is caused by some from of heat or work

Question 8

what type of quantity is work

Answer 8

it is a vector quantity, it points in the direction of the force

Question 9

what component of a force does the work?

Answer 9

the component of the force that is in the same direction as the displacement

Question 10

if there is no force done in the direction of the displacement, is there any work done?

Answer 10

no

Question 11

what is the sign of the work dependent on

Answer 11

it is dependent on the force and the displacement and where it points

Question 12

when does a force do no work?

Answer 12

when the object undergoes no displacement

when the force is perpendicular to the displacement

when the part of the object that is acted on by the force undergoes no displacement

Question 13

what is kinetic energy

Answer 13

it is the energy of motion

Question 14

what type of quantity is kinetic energy, what sign is it?

Answer 14

kinetic energy is always positive and it is a scaler

Question 15

what is potential energy

Answer 15

it is stored energy that has the potential to do work later

Question 16

what are conservative forces?

Answer 16

they are forces that store energy, Gravity and elastic forces

Question 17

what are nonconservative forces?

Answer 17

they are forces that do not store energy, friction

Question 18

what is gravitational potential energy

Answer 18

when lifting/lowering an object, we provide an upwards/downwards force that is converted to gravitational potential energy

Question 19

when lifting heavier objects, what is true about the work put in and the gravitational potential energy

Answer 19

there is more work done which results in more potential energy

Question 20

what is elastic potential energy

Answer 20

it is stored energy when a force compresses a spring

Question 21

is elastic potential energy positive or negative

Answer 21

its always positive

Question 22

what is thermal energy

Answer 22

heat can cause an exchange of energy out of a system

Question 23

friction on a moving object does what?

Answer 23

it does work

Question 24

what does the work caused by friction do?

Answer 24

it creates thermal energy

Question 25

when we only have gravitational potential energy, kinetic energy, and elastic potential energy, what happens to the mechanical energy

Answer 25

the mechanical energy is conserved, we can transfer between these without losing energy

Question 26

what is a perfectly inelastic collision

Answer 26

it is when colliding objects stick together and move with a final common velocity

Question 27

what is a perfectly elastic collision?

Answer 27

it is a collision where mechanical energy is conserved

Question 28

what is power

Answer 28

it is the change in energy transformed or transferred per unit of time

Question 29

momentum is ________ in all collisions, whereas mechanical energy is conserved in _______

Answer 29

momentum is conserved in all collisions whereas mechanical energy is only conserved in a perfectly elastic collision

Question 30

what is the sign of work determined by

Answer 30

it is determined by the angle of the force relative o the displacement

Question 31

if work is negative, what does it mean about the energy transfer

Answer 31

it means energy is transferred out of a system

Question 32

if work is positive what does it mean about the energy transfer

Answer 32

it means energy is transferred into a system

Question 33

how do we find out how much energy is in a spring?

Answer 33

we apply an external force that preforms work on the spring which transfers energy into it to be transformed into elastic potential energy