Types of forces

• Science
• Secondary Education

Recap 1: What are the types of forces?

Recap 2: Forces can.............

Force is measured using

1. Kilogram
2. Kilometer
3. Watt
4. Newton

Force is divided into:

1. Contact force

Example: Impact, friction

2. Non contact force

Example:Magenetic

Tension force

When materials are stretched or squeeze, they exerts force that acts in opposite direction

Tension is a strain exerted when spring, rope or string

Mostly happens to elastic materials so that material can restore to original shape

Impact force

Happens when moving object collide with stationery object

or

Two moving object

Might change the direction and shape of the object

Friction

• Occurs between object and surface during push or pull activity
• Acts in opposite direction
• Static friction is a type of friction where two things touch each other and do not move.

Thinking hat: What happen when there is no friction force in the world?

Give an example in your daily life where friction occurs

Gravitational force

• Force between two masses in the universe
• Pull object toward the centre of the earth
• This is called weight

Mass and weight are the same

AGREE

DISAGREE

Mass and weight

• Mass dercribe how much matter in an object
• Mass is the same no matter where object is located
• Weight is a force that depends on strength of gravitational field
• The bigger the mass of objects the higher magnitude of gravity

Object with mass of 50kg on earth has the mass of 50kg on the Moon

1. True
2. False

Ms Mint is weighs lighter on the Moon

1. True
2. False

Electrostatic Force

A force is exerted between any two charged objects.

Same charged object repel each other

Opposite charged object attract each other

Sparks can be produced when the amount of charge is big

Positive charge attract positive charged object

1. Trues
2. False

Magnetic force

An attractive or repulsive force that is exerted between the poles of a magnet

Attracts object made of iron

The poles of a magnet are east and west

1. True
2. False

Air resistance

Force exerts by the air as you move

Slows you down

Also called the drag force

Why do we need air resistance?

Normal force

A force that the ground (or any surface) pushes back up 

All are forces except

1. Tension
2. Gravitational
3. Compact
4. Friction

TEST YOUR UNDERSTANDING

Quizziz Time

https://quizizz.com

Experiment

Aim: To investigate how shape affects air resistance

Materials: 4 sheets of paper

Prodecure: Use four sheet of paper to make following shape:

a) one sheet flat

b) lightly crumple

c) crumpled into a sphere

d) wad into a ball

Experiment

1. Result and conclusion:
2. Describe how each piece of paper fall
3. Do you get the same result when you repeat the experiment
4. List shapes from fastest to slowest
5. List shapes from least resistance to most resistance
6. Which shape experience most resistance? Why?
7. Which shape experience least resistance? Why?
8. If you are skydiving, do you choose a larger or smaller parachute? Explain why?