Energy Transfers and Equations

Question 1

Kinetic Energy Equation

Answer 1

KE=1/2mv²
KE = 1/2 x mass x speed²

Question 2

Gravitational Potential Energy Equation

Answer 2

GPE=mgh
GPE= mass x gravitational field strength x height

Question 3

Work Done Equation

Answer 3

Ew=Fd
Work Done= Force x Distance

Question 4

Energy Equation

Answer 4

E=Pt
Energy = Power x Time

Question 5

Efficiency Equation

Answer 5

Efficiency=Useful output/Total input

Question 6

Speed Equation

Answer 6

v=d/t
Speed=Distance/Time

Question 7

Weight Equation

Answer 7

W=mg
Weight = mass x gravitational field strength

Question 8

KE and GPE

Answer 8

KE at bottom = GPE at top
1/2mv² (bottom)= mgh (top)

Question 9

Final speed of falling object Equation

Answer 9

v²=2gh

Speed²=2 x gravitational field strength x height

Question 10

What are the units for mass (m)?

Answer 10

Kilograms (Kg)

Question 11

What are the units for time (t)?

Answer 11

Seconds (s)

Question 12

What are the units for distance (d)?

Answer 12

Metres (m)

Question 13

What are the units for height (h)?

Answer 13

Metres (m)

Question 14

What are the units for speed (v)?

Answer 14

Metres per second (m/s)

Question 15

What are the units for force (F)?

Answer 15

Newtons (N)

Question 16

What are the units for weight (W)?

Answer 16

Newtons (N)

Question 17

What are the units for energy (E)?

Answer 17

Joules (J)

Question 18

What are the units for Gravitational Potential Energy (GPE)?

Answer 18

Joules (J)

Question 19

What are the units for Kinetic Energy (KE)?

Answer 19

Joules (J)

Question 20

What are the units for Work Done (Ew)?

Answer 20

Joules (J)

Question 21

What are the units for power (P)?

Answer 21

Watts (W)

Question 22

What are the units for Gravitational field strength (g)?

Answer 22

Newtons per kilogram (N/Kg)

Question 23

What are the units for Efficiency?

Answer 23

None or %
Eg. 0.5=50%

Question 24

Law of conservation of energy

Answer 24

Energy cannot be created or destroyed, only transferred or stored.

Question 25

What are the seven energy stores?

Answer 25

- Magnetic - Thermal - Kinetic - Gravitational Potential - Chemical - Electrostatic - Elastic Potential

Question 26

What is the magnetic energy store?

Answer 26

Magnets that are attracting or repelling.

Question 27

What is the thermal energy store?

Answer 27

The higher the temperature, the higher the energy store

Question 28

What is the kinetic energy store?

Answer 28

Anything that is moving

Question 29

What is the elastic potential energy store?

Answer 29

Anything that has been stretched

Question 30

What is the gravitational potential energy store?

Answer 30

Anything in a gravitational field (anything that can fall)

Question 31

What is the electrostatic energy store?

Answer 31

Two electric charges that attract or repel

Question 32

What is the chemical energy store?

Answer 32

An object/ substance from which energy can be released by a chemical reaction

Question 33

What are the four ways to transfer energy?

Answer 33

- Mechanically - Electrically - Thermally - Radiating

Question 34

How can you transfer energy mechanically?

Answer 34

- As a result of forces - Energy transferred = force x distance

Question 35

How can you transfer energy electrically?

Answer 35

- By flowing electrons in wires - Energy transferred = voltage x charge

Question 36

How can you transfer energy thermally?

Answer 36

- As a result of temperature difference - By conduction, convection or radiation

Question 37

How can you transfer energy by radiating?

Answer 37

- By light or sound waves

Question 38

What does a Sankey diagram show?

Answer 38

The efficiency of specific energy transfers

Question 39

In a Sankey diagram, which value is in the arrow that is straight and at the top?

Answer 39

Useful output

Question 40

Do you draw a Sankey diagram to scale?

Answer 40

Yes

Question 41

In a Sankey diagram, which value is in the arrow that is at the bottom and bent?

Answer 41

The wasted output

Question 42

In a Sankey diagram, what value goes on the left on the straight edge?

Answer 42

The total input