06. P1 Energy

Question 1

What unit is energy measured in?

Answer 1

Joules

Question 2

Name five forms of energy.

Answer 2

Heat, Light, Sound, Chemical, GPE, Ek, Elastic, Electrical, Nuclear

Question 3

What is meant by the conservation of energy?

Answer 3

Total energy into a transfer, must equal the total energy out of the transfer.

Question 4

What is the equation used to calculate percentage efficiency.

Answer 4

(Useful energy out ÷Total energy in) x100

Question 5

Why type of energy is stored in a fossil fuel?

Answer 5

Chemical

Question 6

Why type of energy is stored in food?

Answer 6

Chemical

Question 7

What is the difference between a filament lamp and an energy saving bulb?

Answer 7

Filament lamp is less efficient, so for the same energy out it uses more electrical energy. Wastes more energy as light.

Question 8

What is the energy transfer of a petrol motor?

Answer 8

Chemical -> Kinetic + heat + sound

Question 9

Name three items which use motors.

Answer 9

CD players, washing machines, food processors, games consoles, toothbrush, remote control cars, mobile phones (vibration), hairdrier…….

Question 10

What does GPE stand for?

Answer 10

Gravitational Potential Energy

Question 11

Which equation connects GPE and mass?

Answer 11

GPE = m x g x h

Question 12

What are the units of GPE?

Answer 12

Joules

Question 13

Name one object which has Elastic Potential Energy stored in it.

Answer 13

stretched elastic band, bow (and arrow), fishing line under tension, wind up toy …..

Question 14

What type of object has Kinetic Energy?

Answer 14

Any moving object

Question 15

Which Equation connects Kinetic Energy and Velocity?

Answer 15

Ek = 0.5 x m x v2

Question 16

If you double the velocity, what happens to the kinetic energy?

Answer 16

Double velocity = quadrupled kinetic energy

Question 17

What is the energy transfer of a child going down a slide?

Answer 17

GPE -> Kinetic + heat

Question 18

What are the units of work done?

Answer 18

Joules

Question 19

What equation can you use to calculate the work done by a force?

Answer 19

Work done = Force x distance

Question 20

Which Equation connects Power and Energy?

Answer 20

Power = Energy ÷ time or Energy = Power x time

Question 21

Which unit is Power measured in?

Answer 21

Watts

Question 22

What can be used in an object in order to reduce friction between moving parts?

Answer 22

Oil or lubrication

Question 23

How many watts are in 5 Megawatts?

Answer 23

5MW = 5,000,000 W

Question 24

Hoe many joules are in 2 kilojoules?

Answer 24

2kJ = 2,000 J

Question 25

How many joules does a 10 watt speaker give out in 1 minute?

Answer 25

E = P x t = 10 x 60 = 600J

Question 26

What happens to the kinetic energy of an object if you double the objects mass but it remains at the same speed?

Answer 26

If mass doubles, kinetic energy doubles

Question 27

Friction is a force which acts between two objects moving past each other. What is the effect does friction have on its surroundings?

Answer 27

Friction causes heat wasted to the surroundings (warms the surrounding objects like air etc.)

Question 28

What is the energy store in a candle?

Answer 28

Chemical

Question 29

Which store of energy does a moving car have?

Answer 29

Kinetic

Question 30

What is the change in energy store for a falling object?

Answer 30

Gravitational transfering to Kinetic