Energy

Question 1

8 energy stores:

Answer 1

• Gravitational potential
• Elastic potential
• Chemical
• Electrostatic
• Nuclear
• Thermal (Internal)
• Kinetic
• Magnetic

Question 2

Energy Transfers:

Answer 2

• Radiation
• Mechanically
• Heating
• Electrically

Question 3

2 types of Work Done:

Answer 3

• Mechanical (using force to move an object)
• Electrical (flow of current)

Question 4

Law of conservation of energy.

Answer 4

Energy cannot be destroyed or created; it can only be stored and transferred.

Question 5

Systems.

Answer 5

An object or group of objects.

Question 6

Linking Ep and Ek.

Answer 6

(In a closed system)
Ep at the top = Ek at the bottom
mgh = 1/2mv^2

Question 7

What is dissipation?

Answer 7

When energy is transferred to a less useful energy source/ form.

Question 8

Give two examples of dissipation:

Answer 8

-Sound Waves
-Heating the surroundings

Question 9

Definition of specific heat capacity.

Answer 9

Amount of energy needed to raise the temperature of 1kg of a substance by 1*C

Question 10

Internal energy

Answer 10

Total energy stored by the particles making up a substance or system.

Question 11

How does heating a substance lead to increase in temperature? (In terms of internal energy)

Answer 11

Energy is transferred (via heating) from the source of the heat to the particles in the substance.
The particles have an increase of internal energy.
This increase is measured as an increase in temperature.

(Temperature is simply a measure of average internal energy)

Question 12

Why does material, with a higher specific heat capacity, cool down and heat up slowly?

Answer 12

It takes more energy to change its temperature.

Question 13

What is the method of working out the specific heat capacity of a material?

Answer 13

Measure the mass of the material using a scale
Place the immersion heater into the middle hole at the top and connect the heater to a power pack.
Put the thermometer into the smaller hole and add water/oil into it
Fully insulate the material by wrapping cotton around it so there will be less heat loss
Record the initial temperature of the material
Set the timer for 10 minutes and turn on the power pack, which should be at 10 volts (DC)
Record the temperature at regular intervals. Also record the reading on the Voltmeter and ammeter (however they should stay around the same)
Turn off the power pack once 10 minutes have passed.
Work out the change in temperature by subtracting the initial temperature from the highest temperature.

Use the specific heat capacity equation =
C = e/mt
Where: ….(you get the point) involve measurements!! Like kg
And use: e = vit to work out the energy transferred
Where: …..(etc etc)

Hazard = hot immersion heater
Risk = burning yourself
Reduce risk = allow to cool before handling
If occurs = keep burn under cool water