Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ScienceKS3 > Conservation and Dissipation of Energy > Flashcards

Conservation and Dissipation of Energy Flashcards

1
Q

What is the unit of energy?

A

Joules (J)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the different types of energy stores?

A

Chemical, kinetic, gravitational potential, elastic potential and thermal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the Law of Conservation of Energy?

A

Energy cannot be created or destroyed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is work?

A

Work is done on an object when a force causes the object to move

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How does the energy transferred effect the work?

A

Energy transferred = Work done

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the relationship between work and friction? Give some examples.

A

Work need to be done to overcome friction between objects. Examples are:

• Rubbing hands together
• Brake pads/discs
• Meteorites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does a gravitational potential energy store work?

A

Increases as an object is moved higher, decreases as an object is moved lower.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a kinetic energy store?

A

The energy an object has because it is moving.
Faster = more KE
Heavier = more KE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the equation for work done?

A

Work Done = Force x Distance (W=Fxs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the equation for gravitational potential energy?

A

GPE = Mass x Gravitational Field Strength x Height
Ep =mxgxΔh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the equation for kinetic energy?

A

KE = 0.5 x mass x speed2 (Ek =0.5xmxv2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is useful energy?

A

Where energy is transferred to where it is wanted in the way it is wanted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is wasted energy?

A

Energy that is not usefully transferred

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is dissipation?

A

Wasted energy that is transferred to the internal energy of the surroundings and gets spread out.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is efficiency?

A

How much of the energy transferred to a system is transferred usefully. Can be a decimal (e.g. 0.25) or a percentage (e.g. 25%).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is an electrical appliance?

A

A device that transfers electrical energy into useful energy e.g. TV, toaster, motor, heater, kettle.

17
Q

What is power (P)?

A

•How much energy is transferred per second.
•Measured in Watts, W.
•More powerful device = more energy transferred per second.

18
Q

How can power be used to work out efficiency?

A

•Power can be used to work out efficiency because power is a rate of energy transfer.
•Useful Power output = useful energy transferred per second.
•Total power input = energy transferred per second.
•Can also be a decimal or a percentage.

19
Q

What is the equation for wasted power?

A

Power wasted = total power in – useful power out.

20
Q

What is the equation for efficiency?

A

Useful output energy ÷ Total input energy

21
Q

What is the equation for power?

A

Power = Energy ÷ Time (P=E÷t)

22
Q

What is another equation for efficiency?

A

Efficiency = Useful power out ÷ Total power in

ScienceKS3 (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions