Topic 1-Energy Flashcards Preview

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Flashcards in Topic 1-Energy Deck (51)
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1

When energy is transferred to an object the energy is stored in...

The objects energy stores.

2

What are the 8 energy stores?

-Thermal
-Kinetic
-Gravitational potential
-Elastic potential
-Chemical
-Magnetic
-Electrostatic
-Nuclear

3

What could energy stores also be called?

Internal energy stores.

4

How can energy be transferred?

-Mechanically
-Electrically
-Heating
-Radiation

5

What is a system?

A word for a single object that you are interested in.

6

What is a closed system?

A system which neither matter nor energy can enter or leave.

7

The net change in the total energy of a closed system is always ...

zero.

8

When a system changes energy is ...

Transferred.

9

Work done is another way of saying ...

Energy transferred.

10

When can work done happen?

When current flows or when a force is moving an object.

11

Any thing that is moving has energy in what type of store?

Kinetic.

12

What is the equation for kinetic energy?

kinetic energy=1/2 x mass x velocity squared.

13

What is the equation for gravitational potential energy?

G.P.E=mass x gravitational field strength x height.

14

What is the equation for elastic potential stores?

Elastic potential energy= 1/2 x spring constant x extension squared.

15

What is the equation for change in thermal energy?

change in thermal energy=mass x specific heat capacity x temperature change.

16

What is specific heat capacity?

It is the amount of energy needed needed to raise the temperature by one degree.

17

How do you investigate the specific heat capacity of a solid?(6 marker)

1)measure the mass of the block, then wrap it in an insulating layer.
2)measure the initial temperature and set the potential difference to 10V.
3)Turn on the power supply and start a stop watch.
4)As the block heats up take readings of the current in the circuit.
5)Using the potential difference and current calculate power. Then use it to calculate how much energy has been transferred using the formula E=Pt.

18

What is the conservation of energy principle?

It is that energy can be transferred usefully,stored or dissipated, but can never be created or destroyed.

19

What is dissipated energy?

Energy that is stored in a way that is not useful.

20

What is power?

Power is the rate of energy transfer, or the rate of doing work.

21

What is power measured in?

Watts.

22

How do you work out power with work done?

power=work done divided by time.

23

How do you calculate power with energy transferred?

power=energy transferred divided by time.

24

What is conduction?

Conduction is the process where vibrating particles transfer energy to neighbouring particles.

25

Energy transferred to an object by heating is stored in the...

Thermal store.

26

What is thermal conductivity?

Thermal conductivity is a measure of how quickly energy is transferred through a material by conduction.

27

What is convection?

Convection is where energetic particles move away from hotter to cooler regions.

28

How is a convection current created?

1)Energy is transferred by heating to the thermal store of the liquid or gas.
2)The particles in a liquid or gas can move so the particles move faster and the space between the individual particles increases.
3)this causes the density to decrease.
4)The warmer and less dense region will rise above denser,cooler regions.
5)with a constant heat source a convection current is created.

29

What can you do in a house to prevent energy losses except heating?

-Have thick walls that are made from a material with a low conductivity.
-Use thermal insulation such as cavity wall insulation, loft insulation or draught excluders.

30

How can you improve an objects efficiency.

-Insulation.
-Lubrication.
-Making them more streamlined.