Physics Test (Year 8)

Question 1

How do you calculate power?

Answer 1

power (w) =

energy (j)
________
time (s)

Question 2

How do you calculate the work done?

Answer 2

work done (j) =

force (N) x distance (m)

Question 3

What does the speed, distance, time triangle look like?

Answer 3

/ D \
/ S | T \
______

Question 4

How do you calculate pressure?

Answer 4

pressure (N/m²) =

force (N)
________
area (m²)

Question 5

How do you calculate the moment (turning force)?

Answer 5

moment (Nm) =

force (N) x distance from pivot (m)

Question 6

How do you calculate current?

Answer 6

current (A) =

potential difference (v)
_________________
resistance (Ω)

Question 7

How do you calculate resistance?

Answer 7

resistance (Ω) =

potential difference (v)
_________________
current (A)

Question 8

What does the resistance, potential difference and current triangle look like?

Answer 8

/ V \
/ A | R \
______

Question 9

You are driving a car at 60mph. Another car is travelling in the same direction as you at the same speed.
What is the relative speed?

Answer 9

0

Question 10

Two cars are moving at each other at 30mph.

What is the relative speed?

Answer 10

60mph

Question 11

What charge do protons have?

Answer 11

Positive

Question 12

What charge do electrons have?

Answer 12

Negative

Question 13

What charge do neutrons have?

Answer 13

They have no charge.

Question 14

What is an electric field?

Answer 14

A region where a charged material or particle experiences a force.

Question 15

What is potential difference?

Answer 15

A measure of the push of a cell or battery, or the energy that the cell or battery can supply.

Question 16

How can energy be transferred?

Answer 16

Through:
Conduction
Convection
Radiation

Question 17

What is conduction?

Answer 17

The way in which energy is transferred through solids, and to a much lesser extent in liquids and gases.

Question 18

What is convection?

Answer 18

The transfer of energy by the movement of heated liquids or gasses.

Question 19

What is radiation?

Answer 19

The transfer of energy as a wave.

Question 20

What happens when you heat a solid?

Answer 20

The particles vibrate more.

Question 21

What happens when you heat a liquid or a gas?

Answer 21

The particles move faster and vibrate more.

Question 22

Explain the law of conservation of energy.

Answer 22

Energy cannot be created or destroyed, only transferred.

Question 23

Explain the law of moments.

Answer 23

An object is in equilibrium if the clockwise moments equal the anticlockwise moments.

Question 24

What piece of equipment is used to measure potential difference?

Answer 24

Voltmeter

Question 25

In a series circuit which is the same for each component?

Answer 25

Current

Question 26

How can you increase the strength of an electromagnet?

Answer 26

Increase the current
Increase the number of turns
Add an iron core

Question 27

Define current.

Answer 27

Current is the flow of charge.

Question 28

What piece of equipment is used to measure current?

Answer 28

Ammeter

Question 29

Define potential difference.

Answer 29

A measure of the push of a cell or battery or the energy that the cell can supply.

Question 30

Give the unit for potential difference.

Answer 30

Volts

v

Question 31

Give the unit for current.

Answer 31

Amperes or Amps.

A

Question 32

What pieces of equipment would you need to investigate a magnetic field?

Answer 32

A bar magnet, plotting compasses or iron filings and some paper.

Question 33

How do you calculate the relative motion/velocity?

Answer 33

Object A speed - Object B speed

Question 34

How do you calculate the relative motion/velocity if the objects are travelling in opposite directions?

Answer 34

Object A speed - (-Object B speed)