F4 Physics GS Test

Question 1

Formula for pressure in solids

Answer 1

P = F/A
(Pressure = Force/Area)

Question 2

Formula for pressure in liquids

Answer 2

P = hgρ
(Pressure = Height x Gravity x Density)

Question 3

Formula for pressure in gases

Answer 3

P ∝ 1/V
(Pressure is directly proportional to 1/Volume)

Question 4

What is the unit for pressure?

Answer 4

Pa OR N/m²
(Pascal OR Newton/squared meter)

Question 5

Why do solids and liquids expand when heated?

Answer 5

Because of the hotter environment, particles speed up and will vibrate more. Their vibrations take up more space, so the solid/liquid expands slightly in all directions.

Question 6

What is thermal expansion?

Answer 6

The effect that happens to liquids and solids where they expand due to the hot environment around them.

Question 7

Why would it not be a good idea to reinforce concrete with aluminium rods?

Answer 7

Because aluminium expands more than concrete, so the aluminium rods would crack the concrete.

Question 8

Why does water expand when it freezes?

Answer 8

The particles in the water (liquid particles) need to re-arrange to become particles in the ice (solid particles). This causes the water to expand a little.

Question 9

What is contraction?

Answer 9

The opposite of expansion - Solids and liquids will contract slightly due to the cold environment (because of the cold, the particles move more slowly and therefore occupy less space)

Question 10

What is temperature?

Answer 10

The average kinetic energy between molecules.

Question 11

How do you calibrate a thermometer?

Answer 11

By finding and marking the ice point and the boiling point.

Question 12

Name the properties of a thermometer

Answer 12

Range
Sensitivity
Linearity
Responsiveness

Question 13

Name 4 ways that heat can be transferred by

Answer 13

Conduction
Convection
Radiation
Evaporation

Question 14

Why are metals good conductors of heat?

Answer 14

Because they have atoms with lots of free electrons
Because the heat energy is passed on by neighbouring particles vibrating along the metal

Question 15

Why are non-metals poor conductors of heat?

Answer 15

Because they do not have free electrons

Question 16

Conductor or Insulator:
Metals: ______
Non-metals: ______
Liquids: ______
Gases: ______
Vacuum: ______

Answer 16

Metals: CONDUCTOR
Non-metals: INSULATOR
Liquids: INSULATOR
Gases: INSULATOR
Vacuum: CONDUCTOR

Question 17

Convection happens mainly in ______.

Answer 17

Fluids (liquids and gases)

Question 18

What is convection?

Answer 18

The transfer of heat caused by hotter material to rise and colder material to sink under the influence of gravity.

Question 19

Give one example of convection

Answer 19

Boiling water

Question 20

What is conduction?

Answer 20

The process by which heat energy is transmitted through collisions between neighboring atoms or molecules in solids.

Question 21

Give one example of conduction

Answer 21

Using a metal ladle on a hot pan (the heat will transfer from inside the pan to the handle of the ladle)

Question 22

What is radiation?

Answer 22

Heat traveling through infrared rays (like light waves, but with a longer wavelength)

Question 23

Give one example of radiation

Answer 23

Standing near a fireplace/campfire and feeling its heat when nearby it

Question 24

Dark colours are good ______ and good ______.

Answer 24

emitters, absorbers

Question 25

Bright or shiny colours are ______ emitters and absorbers.

Answer 25

poor