Forces

Question 1

What is a force?

Answer 1

A push or pull on an object due to its interaction with another object?

Question 2

What is the unit used to measure force?

Answer 2

Newton (N)

Question 3

What instrument do we use to measure a force?

Answer 3

Spring balance

Question 4

Can force be measured?

Answer 4

Yes, a force is a physical quantity.

Question 5

What physical quantities does a force have?

Answer 5

Size and direction.

Question 6

What are these types of physical quantities (size and direction) called?

Answer 6

Vectors

Question 7

How can vectors be represented?

Answer 7

By an arrow which is drawn to scale.

Question 8

What does the length of the arrow represent?

Answer 8

The size

Question 9

What does the arrowhead tell us?

Answer 9

The direction.

Question 10

How else can direction be given?

Answer 10

Cardinal points or as bearing.

Question 11

What are the effects of force?

Answer 11

Alter the motion of an object (moving to stationary/stationery to moving)

Change direction of a moving object.

Change shape of object by exerting a force.

Change the speed of an already moving object.

Question 12

When is the net force great than 0N?

Answer 12

When forces are acting in opposite directions, but aren’t equal.

Question 13

What are the two types of forces?

Answer 13

Contact and non-contact forces.

Question 14

What is a contact force?

Answer 14

A force that results when two objects are physically touching each other.

Question 15

What is a non-contact force?

Answer 15

A force that can act over a distance. This means that the two objects have an effect on one another even when they are not touching each other.

Question 16

What is friction force?

Answer 16

Simple: a force that opposes motion.

The resistance that one surface or object experience when moving over another surface or object, or through a substance (liquid or gas).

Question 17

Which direction do friction forces always act in?

Answer 17

The opposite direction to the motion of the object.

Question 18

What does the size of frictional forge depend on?

Answer 18

The type of surface on which an object is moving (the smoother the surface the less friction there is)

The normal surface (acts in opposite direction to the weight of object)

Question 19

What is the normal force?

Answer 19

It’s a contact force that prevents you from penetrating the ground. It always acts perpendicularly to the surface that the object is resting on.

Question 20

What are the advantages of friction forces?

Answer 20

Friction between our feet and the ground enables us to move forward without slipping.

Friction between the tread at a rude and the road prevents cars from slipping.

Question 21

What is a tension force?

Answer 21

Two forces acting on one object in opposite directions (away from each other) to stretch the object/pull it apart.

Question 22

What is a compression force?

Answer 22

Two forces acting on one object in opposite directions (towards each other) to compress or deform the object.

Question 23

What is muscular force (applied force)?

Answer 23

Force applied by a person or an engine on an object.

Must involve a person or engine.

Question 24

What is gravitational force?

Answer 24

A force of attraction (pulling force) between two objects/bodies over a distance due to their masses.

Question 25

What does the size of the gravitational force depend on?

Answer 25

The greater the mass of the objects, the stronger the gravitational force of attraction between them.

The closer the objects are to each other, the strong the gravitational force between them.

Question 26

Name three differences between mass and weight.

Answer 26

Mass: the amount of matter an object consists of.
Weight: gravitational force exerted on the object by the earth (or any other planet).

Mass: measured in kg.
Weight: measured in N

Mass: remains the same whenever it’s measured.
Weight: can change depending on where it is measured.

Question 27

What is the formula to work out the weight?

Answer 27

Mass x gravitational acceleration

Question 28

What type of force is a magnetic force?

Answer 28

Non-contact

Question 29

Which poles attract?

Answer 29

Unlike poles

Question 30

Which poles repel?

Answer 30

Like poles

Question 31

Which direction do the arrows always go in a magnet?

Answer 31

From North to South. (Towards south)

In at south, out at north.

Question 32

When does the strength of a magnetic field weaken?

Answer 32

As you get further away from the magnet.

Question 33

How is electric charge transferred from one object to another in electrostatic forces?

Answer 33

Friction

Question 34

What happens when an object loses electrons?

Answer 34

It will have more protons than electrons and will therefore be positively charged.

Question 35

What happens when an object gains electrons?

Answer 35

It will have more electrons than protons, therefore making it negatively charged.

Question 36

What is an example of a huge electrostatic discharge?

Answer 36

Lightning.

Question 37

What is the gravitational acceleration on Earth?

Answer 37

9.8m/s

Question 38

What is the gravitational acceleration on the moon?

Answer 38

1.6m/s

Question 39

What is an electrostatic force?

Answer 39

A force that electrically charged objects to exert on each other over a distance.

Question 40

What is electrostatic force?

Answer 40

A force that two electrically charged objects exert on each other over a distance.