Energy - physics

Question 1

Specific heat capacity

Answer 1

The amount of energy needed to increase the temperature of 1kg of a substance by 1 degrees C

Question 2

When thrown why does a ball slow down as it rises

Answer 2

Because the energy from the kinetic energy store is being transferred to it’s gravitational potential energy store

Question 3

How does mass differ throughout the universe

Answer 3

It doesn’t - it stays the same

Question 4

What is internal energy

Answer 4

The total energy stored by the particles making up a substance or system

Question 5

How is energy transferred away from a light bulb

Answer 5

• Via light
• By heating

Question 6

Open vs closed system

Answer 6

An open system can exchange energy and matter with it’s surroundings but a closed system cannot.

Question 7

Why do we seal the house

Answer 7

To minimise the heat loss through convection

Question 8

Energy transfers

Answer 8

Mechanical work - a force moving an object through a distance
Electrical work - charges moving due to a
potential difference
Heating - due to temperature difference caused electrically or by chemical reaction
Radiation - energy transferred as a wave, eg light and infrared - light radiation and infrared radiation are
emitted
from the sun

Question 9

What useful energy transfer takes place when a battery powered toy car travels across the floor?

Answer 9

Chemical —-> Kinetic

Question 10

Which factors affect the gravitational force of attraction

Answer 10

• The distance between the objects
• The mass of the objects

Question 11

What do we mean by the term ‘fluid’, and which states of matter are considered fluids?

Answer 11

Particles are free to move, liquids and gases

Question 12

How does conduction work

Answer 12

• As one end of the solid object is heated, energy is transferred to the kinetic energy stores of the particles in that end.
• This causes the p[articles to vibrate faster and so they collide with their neighbouring particles more often.
• As the collisions transfer kinetic energy, their neighbours also vibrate faster and collide more often with their neighbours.
• This process repeats over and over again so that energy is effectively passed along the object from one particle to the next.

Question 13

Can inferred radiation travel through a vacuum

Answer 13

Yes

Question 14

What does convection take place in

Answer 14

• Liquids
• Gases

Question 15

Where does convection take place in

Answer 15

Solids

Question 16

How does convection work

Answer 16

As a fluid is heated the particles gain more kinetic energy and spread further apart. This causes the fluid to become less dense and so it rises abo9ve any cooler fluid that hasn’t been heated. As the fluid cools down it will become more dense again and so sink back down. If this process takes place in a limited space, like a container or a room, it can create a convection current,

Question 17

When does a convection current take place

Answer 17

When convection is taking place in a limited space, like a container or a room.

Question 18

What helps to reduce the loss of convection

Answer 18

-Closing your windows
- Covering yourself with a blanket at night