Potential Energy and Conservation of Energy

Question 1

work done by gravitational force is ___ if the displacement is positive vertically

Answer 1

negative

Question 2

what happens to kinetic energy if the system slows down

Answer 2

decrease

Question 3

loss in kinetic energy translates to gain in ______

Answer 3

potential energy

Question 4

if the displacement is towards the earth, what is the work done by the gravitational force?

Answer 4

positive

Question 5

if the system speeds up, its kinetic energy ____ while the potential energy _____

Answer 5

increases, decreases

Question 6

if a system ascends, its kinetic energy ____ while its potential energy ____

Answer 6

decreases, increases

Question 7

if a system is at its maximum height, its kinetic energy is at ____ while its potential energy is at ____

Answer 7

minumum, maximum

Question 8

if a system descends, its kinetic energy ____ while its potential energy ____

Answer 8

increases, decreases

Question 9

change in potential energy is the ______ work done

Answer 9

negative

Question 10

change in kinetic energy is equal to the ____ of the change in gravitational potential energy (no air resistance/friction)

Answer 10

negative

Question 11

potential energy difference depends only on initial and final position of the particle

T or F?

Answer 11

F. It also depends on some parameters such us spring constant (k)

Question 12

what is total potential energy?

Answer 12

sum of the potential energies of all types

Question 13

what is the formula for work done by the gravitational force?

Answer 13

mgy + const

Question 14

what is the formula for elastic potential energy

Answer 14

1/2 kx^2 +const

Question 15

any transition from kinetic energy to potential energy conserved the ____ of the system

Answer 15

total energy

Question 16

the total energy of the system changes when compared at any two points in conservative forces

T or F?

Answer 16

F. One characteristic of conservative forces is that the total energy of the system is constant at any two points.

Question 17

These forces take energy away from the system

Answer 17

Non-conservative Forces

Question 18

give at least one example of conservative forces

Answer 18

• Gravitational Force

- Spring Force

Question 19

give at least one example of non-conservative forces

Answer 19

• Air resistance

- Friction

Question 20

_____ Forces are path dependent

Answer 20

Non-conservative

Question 21

_____ Forces are path independent

Answer 21

Conservative

Question 22

If KE = 0, the total energy of the system is _____

Answer 22

Potential Energy

Question 23

_____ the force to get the work and change in PE

Answer 23

integrate

Question 24

take the _____ of potential energy to get the force

Answer 24

derivative

Question 25

mechanical energy is the ____

Answer 25

sum of kinetic and potential energy

Question 26

change in mechanical energy is equal to the _____ by the non-conservative forces

Answer 26

work

Question 27

kinetic energy is ___ when going down if air resistance is present

Answer 27

less

Question 28

the speed going down is ____ than the speed going up if air resistance is present

Answer 28

less