Physics 1A

Question 1

Name the 3 ways heat is transferred

Answer 1

Radiation
Conduction
Convection

Question 2

What is heat radiation transferred by ?

Answer 2

Infrared radation

Question 3

What is conduction and convection transferred by ?

Answer 3

Particles

Question 4

What is the main form of heat transfer in solids ?

Answer 4

Conduction

Question 5

What is the main form of heat transfer in liquids and gases ?

Answer 5

Convection

Question 6

What is infrared radiation emitted by ?

Answer 6

Solids, liquids and gases

Question 7

What objects can both emit and absorb infrared radiation?

Answer 7

Any

Question 8

Why can you feel infrared radiation if you stand near something hot ?

Answer 8

An object that’s hotter than it surroundings emits more radiation than it absorbs

Question 9

Why do dark, matt surfaces absorb infrared radiation better than light, shiny surfaces ?

Answer 9

Lights, shiny surfaces reflect more infrared radiation than it absorbs.

Question 10

What is Specific Heat Capacity (SHC)

Answer 10

The amount of energy needed to raise the temperature of 1kg of a substance by 1 degrees.

Question 11

What is the equation to work out Specific Heat Capacity?

Answer 11

Energy transferred= mass x SHC x temperature change

(J) (kg) (J/kg) (C)

Question 12

What is the Kinetic Theory?

Answer 12

It describes how particles move in solids, liquids and gases.

Question 13

What is kinetic energy?

Answer 13

The energy an object/particle has because of its movement.

Question 14

How does Kinetic Theory explain the arrangement of particles within a solid?

Answer 14

1. Strong forces of attraction hold the particles close together in a fixed, regular arrangement
2. The particles don’t have much energy so they can only vibrate about their fixed positions.

Question 15

How does Kinetic Theory explain the arrangement of particles within a liquid?

Answer 15

1. There are weaker forces of attraction between the particles.
2. The particles are close together but can move past each other- forming irregular arrangement
3. They move in random directions at a slow speed

Question 16

How does Kinetic Theory explain the arrangement of particle within a gas?

Answer 16

1. There are almost no forces of attraction between particles
2. They are free to move and travel in random directions at high speeds

Question 17

What happens to a substance if you heat it?

Answer 17

You give the particles more kinetic energy so they vibrate and move faster. This is what causes solids,liquids and gases to boil.

Question 18

In an exam, they may ask you to choose an electrical appliance- How do you pick the best one?

Answer 18

1. You might need to work out which appliance wastes/uses less energy or is more cost effective
2. You may also need to consider the practicality of each appliance
3. Think about advantages and disadvantages

Question 19

How do you work out the cost of electricity?

Answer 19

To work out how much electricity will cost if used for a certain amount of time:
Units= kW x hours

To work out the cost of electricity:
Cost= Units x Price