# 06. P1 Energy Flashcards

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1
Q

﻿What unit is energy measured in?

A

Joules

2
Q

Name five forms of energy.

A

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

3
Q

What is meant by the conservation of energy?

A

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

4
Q

What is the equation used to calculate percentage efficiency.

A

(Useful energy out ÷Total energy in) x100

5
Q

Why type of energy is stored in a fossil fuel?

A

Chemical

6
Q

Why type of energy is stored in food?

A

Chemical

7
Q

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

A

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

8
Q

What is the energy transfer of a petrol motor?

A

Chemical -> Kinetic + heat + sound

9
Q

Name three items which use motors.

A

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

10
Q

What does GPE stand for?

A

Gravitational Potential Energy

11
Q

Which equation connects GPE and mass?

A

GPE = m x g x h

12
Q

What are the units of GPE?

A

Joules

13
Q

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

A

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

14
Q

What type of object has Kinetic Energy?

A

Any moving object

15
Q

Which Equation connects Kinetic Energy and Velocity?

A

Ek = 0.5 x m x v2

16
Q

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

A

Double velocity = quadrupled kinetic energy

17
Q

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

A

GPE -> Kinetic + heat

18
Q

What are the units of work done?

A

Joules

19
Q

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

A

Work done = Force x distance

20
Q

Which Equation connects Power and Energy?

A

Power = Energy ÷ time or Energy = Power x time

21
Q

Which unit is Power measured in?

A

Watts

22
Q

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

A

Oil or lubrication

23
Q

How many watts are in 5 Megawatts?

A

5MW = 5,000,000 W

24
Q

Hoe many joules are in 2 kilojoules?

A

2kJ = 2,000 J

25
Q

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

A

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

26
Q

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

A

If mass doubles, kinetic energy doubles

27
Q

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

A

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

28
Q

What is the energy store in a candle?

A

Chemical

29
Q

Which store of energy does a moving car have?

A

Kinetic

30
Q

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

A

Gravitational transfering to Kinetic