Magnetism

Question 1

What do like and unlike poles do?

Answer 1

Like poles repel, unlike poles attract.

Question 2

What is a compass?

Answer 2

A magnet that is free to rotate.

Question 3

What is a magnetic field?

Answer 3

The space around a magnet where a magnetic force can be seen.

Question 4

Ways to show magnetic fields?

Answer 4

Using iron fillings or plotting compasses.

Question 5

Where do magnetic field lines go?

Answer 5

From the North Pole to the South Pole of the magnet.

Question 6

Materials magnets can be made of?

Answer 6

Iron, steel, cobalt and nickel

These materials = attracted by magnets.

Question 7

Uses of magnets?

Answer 7

Compasses
Scrap yards
Fridge doors

Question 8

How would you plot the magnetic field around a bar magnet using plotting compasses?

Answer 8

Compasses placed around a bar magnet

Pointers point

Question 9

What is magnetism?

Answer 9

The force of attraction

Question 10

Why does a compass always turn North?

Answer 10

Its North Pole is attracted to the earths geographical South Pole

Question 11

Define a force

Answer 11

Something that causes an object to change speed or direction

Question 12

What are forces measured in?

Answer 12

Newtons (N)

Question 13

Name some examples of force

Answer 13

Push, pull, friction, magnetic, Gravity, weight.

Question 14

Name an instrument used to measure a force

Answer 14

Spring balance

Question 15

Define weight

Answer 15

The weight of an object on the earth is the force of attraction between the earth and the object

Question 16

What is weight measured in?

Answer 16

Newtons

Question 17

What is the force formula to find something’s weight?

Answer 17

Weight= mass (in kg) x acceleration due to gravity (10)

Question 18

Acceleration an object gets from the earth?

Answer 18

Is the same for all objects (10m/s²)

Question 19

Distinguish between mass and weight

Answer 19

Mass

- Measured in kg
- Fixed (never changes)
- Fixed feature of all things 

Weight

- newtons
- varies and depends on where you are
- is a force or pull on something

Question 20

State Hooke’s Law

Answer 20

The extension of a spring depends on the size of the weight attached to it

Question 21

What is a moment??

Answer 21

How much force can turn on a object

Question 22

Moment formula

Answer 22

Force x distance from the fulcrum

Question 23

Explain what a lever and fulcrum are.

Answer 23

A lever is a rigid body which is free to rotate about a fixed point called a fulcrum.

Question 24

What is an example of a fulcrum?

Answer 24

The middle of a seesaw

Question 25

What is an example of levers?

Answer 25

Door, door handle, scissors

Question 26

State the law of the lever

Answer 26

When a lever is balanced the sum of clockwise movements = the sum of anti clockwise movements

Question 27

What is the centre of gravity on an object

Answer 27

Centre where All the weight of the object appears to act.
i.e centre of weight

e.g you can balance a Pen on a finger if the finger is a the pen’s centre of gravity (if not the one will fall)

Question 28

What needs to happen for an object to be stable under gravity

Answer 28

Centre of gravity should be low as possible

Area of base should be large as possible

Question 29

What is equilibrium?

Answer 29

When an object is balanced it needs to

• not topple easily when a small force is applied
• it is unstable equilibrium if it will topple easily when small force is applied