Energy Transfers

Question 1

Give an example of a chemical store

Answer 1

battery

coal- fuel

food

Question 2

Give an example of a nuclear store

Answer 2

Uranium in a nuclear power station

Fusion occurring in the Sun

Question 3

Name the energy store depleted and filled when a roller coaster accelerates down the first slope.

Answer 3

Gravitational store of the roller coaster is being depleted

Kinetic store of the roller coaster is being filled along with the thermal store of the track, wheels and surroundings.

Energy is also shifted/transferred away via radiation of sound

Question 4

What is the law of conservation of energy?

Answer 4

Energy cannot be created nor destroyed, only transferred from one store to another.

Question 5

Use the conservation of energy to work out how much energy is used for respiration in a cow.

Answer 5

Conservation of energy is energy cannot be created nor destroyed, it is only transferred from one store to another.

100kJ = Energy In

4kJ + 63kJ + ? = Energy Out

33kJ of energy goes to respiration in the cow

Question 6

Give an example of a kinetic store

Answer 6

car, moving

spaceship, moving

bullet moving

generator turning

Question 7

Give an example of a thermal store

Answer 7

hot pan

hot water in a kettle

the filament in a toaster

a human body

Question 8

What are the 8 stores of energy?

Answer 8

Chemical

Thermal

Gravitational

Kinetic

Vibrational

Nuclear

Electrostatic & magnetic

Elastic

Question 9

How does energy transfer or shift from a stretched elastic in a catapult to moving stone?

Answer 9

mechanically- elastic exerts a force on the stone

• Elastic store of elastic is emptied*
• Kinetic store of stone is filled*

Question 10

What energy store is depleted and which energy store is filled when the popper toy is release.

How is this energy transferred from one store to another?

Answer 10

Elastic store of popper toy is depleted

Kinetic store of popper toy is filled

This energy is transferred mechanically via a spring force

Question 11

Give an example of electrostatic & magnetic energy store

(one of each!)

Answer 11

Electrostatic

Two similarly charged particles near each other

Charged van de Graaf generator

Magnetic

North and north pole of a magnet pushed together

North pole of a magnet and south pole of an electromagnet pulling in a speaker cone

Question 12

What is the equation for efficiency?

Answer 12

Question 13

Give an example of gravitational store

Answer 13

Water behind a dam

Person at the top of a slide

Spaceship in orbit around Earth

Question 14

How does energy transfer or shift from a stretched elastic in a catapult to moving stone?

Answer 14

mechanically- elastic exerts a force on the stone

• Elastic store of elastic is emptied*
• Kinetic store of stone is filled*

Question 15

What store of energy does this boulder possess?

Answer 15

Gravitational store

Question 16

How is energy shifted/transferred from the gravitational store of the rollercoaster to kinetic store of the rollercoaster as it accelerates down the slope?

Answer 16

Energy is shifted mechanically by the force of gravity

Question 17

What energy store does this hot cup of tea have?

Answer 17

Thermal store

Question 18

What energy store is depleted and which energy store is filled when the popper toy is moving upward.

How is the energy transferred from one store to another?

Answer 18

Kinetic store of popper toy is depleted

Gravitational store of popper is filled

Energy is transferred mechanically via the force of gravity

Question 19

What energy store is depleted and which energy store is filled when the popper toy is release.

How is this energy transferred from one store to another?

Answer 19

Elastic store of popper toy is depleted

Kinetic store of popper toy is filled

This energy is transferred mechanically via a spring force

Question 20

Give an example of an elastic store

Answer 20

stretched elastic in a catapult

bent ruler

stretched spring in a clockwork toy

Question 21

How is Sankey diagram constructed?

Answer 21

• using graph paper
• create a scale- e.g. one small square = 10J

If Total Energy In is= 200J arrow should be 20 squares in width to start.

Useful Energy Out - straight arrow forward

5 squares = 50J

-Wasted Energy Out -arrow curling downward

15 squares = 150J

Question 22

List the four ways in which energy can be shifted or transferred

Answer 22

mechnically- by a force

electrically- movement of charge

radiation- light or sound

heating- hot to cold

Question 23

What energy store is being filled as this hot cup of tea cools?

Answer 23

Thermal store of surroundings (air, table etc)

Question 24

What is conduction?

Answer 24

Conduction occurs when heat is transferred through a material from particle to particle

Question 25

Energy is stored chemically in the match. How is energy transferred or shifted from the match? Which energy store is being filled?

Answer 25

**Chemical store** the match is **emptied**. This energy is shifted/transferred away from the match by **radiation (light)** and **heating** to the surroundings. The **thermal store** of **the surrounding is being filled**

Question 26

What energy store is depleted and which energy store is filled as water rushes down the tunnels from a hydroelectric dam to the turbines below?

Answer 26

**Gravitational store** of the water is **depleted** and **kinetic store** of water is **filled**.

Question 27

Which cup will radiate the most heat?

Answer 27

The cup at 80°C will radiate the most heat to the surroundings. The greater the temperature difference the greater the rate of heat transfer.

Question 28

A cannon ball used explosives to launch a ball into the air. Which is an unwanted energy transfer that occurs whent he cannon is fired? ## Footnote A. Chemical store of explosives --\> kinetic store of ball B. Chemical store of explosives --\> Gravitational store of ball C. Chemical store of explosives --\> Thermal store of ball

Answer 28

C. Chemical store of explosives --\> Thermal store of ball