4.1.1.1 Energy Stores and Systems

Question 1

System:

Answer 1

an object or group of objects we choose to model with equations

Question 2

What happens when a system changes?

Answer 2

there is a change in the way E is stored when a system changes

Question 3

What are all the E stores?

Answer 3

• elastic potential store
• gravitational potential store
• kinetic store
• chemical store
• thermal store
• magnetic/electromagnetic store
• nuclear store
• electrostatic store

Question 4

Elastic potential store:

Answer 4

• Any object that is being stretched or compressed

- The more it is stretched/compressed the more E it has in its elastic potential E store

Question 5

Gravitational potential store:

Answer 5

• Anything that has mass and is inside a gravitational field has a E in its gravitational potential store
• The higher up it is the more E it has in its gravitational potential store

Question 6

Kinetic Store:

Answer 6

Anything that is moving has E in its kinetic E store

Question 7

Chemical store:

Answer 7

• Anything that can release E through a chemical reaction such as food, fuels and batteries
• Foods like bread have more E in their chemical store than foods like lettuce

Question 8

Thermal store:

Answer 8

• All objects have E in their thermal E store

- The hotter an object is the more E it has in its thermal E store

Question 9

Magnetic/electromagnetic store:

Answer 9

Anything magnetic object that is interacting with another magnet

Question 10

Nuclear store:

Answer 10

Atomic nuclei have E in their nuclear store that can be released in nuclear reactions

Question 11

Electrostatic store:

Answer 11

Anything with electric charge interacting with another electric charge

Question 12

What is the E transfer needed to score a goal in the top corner of a goal?

Answer 12

Chemical store (of person) –> gravitational potential store (of ball) + thermal store (of the surroundings)

Question 13

What is the E transfer that takes place when a car stops?

Answer 13

Kinetic store (of car) –> thermal store (of break pads) + thermal store (of surroundings)

Question 14

What E transfer takes place for when a battery powered fan turns on and then off?

Answer 14

Chemical store (of fan battery) –> kinetic store (of fan) + thermal store (of fan)

Question 15

What energy transfer takes place when a beaker of hot water cools?

Answer 15

Thermal store (of water) –> kinetic store (of hot air rising) + thermal store (of surroundings)

Question 16

What E transfer takes place when pushing a toy car up a slope from the bottom to the top of the slope?

Answer 16

Chemical store (of hand) –> gravitational potential store (of car) + thermal store (of wheels) + thermal store (of air)

Question 17

What E transfer takes place when pushing magnets together. From far apart to closer together?

Answer 17

Chemical store (of arm) –> electromagnetic store (of magnets) + thermal store (of surroundings)

Question 18

What energy transfer takes place for wind up toy from when it is wound up ready to go to when it has wound down?

Answer 18

Elastic potential store (of car spring) –> kinetic store (of car) + thermal store (of car) + thermal store (of surroundings)

Question 19

What E transfer takes place for ball rolling down a slope from when it is stationary to the top to rolling at the bottom of the slope?

Answer 19

Gravitational potential store (of ball) –> thermal store (of ball) + thermal store (of surroundings) + kinetic store (of ball)

Question 20

Describe the changes in energy in a closed system:

Answer 20

In a closed system there is no net change of total energy e.g. in the absence of air resistance all the energy from the kinetic store will be transferred to the gravitational potential store when the object is pushed upwards

Question 21

Describe the energy changes that take place when an object hits an obstacle:

Answer 21

Kinetic store (of object) ——> (via mechanical pathway) gravitational potential store (of object) + thermal store (of object) + thermal store (of surroundings)

Question 22

What energy change takes place when an object is accelerated by a constant force?

Answer 22

chemical store (of car) ——> kinetic store (of car)

Question 23

What energy change takes place when an object is slowing down?

Answer 23

Kinetic store (of vehicle) —→ (energy dissipated through heat and sound) thermal store (of break pads) + thermal store (of surroundings)

Question 24

What energy change takes place when an object is being deformed?

Answer 24

object —→ (via mechanical pathway) elastic potential store