Topic 2: Forces

Which of the following are non-contact forces? (2 answers)

• frictional force

• magnetic force

• elastic force

• gravitational force

Answer explanation

A contact force is any force that occurs as a results of two objects in contact with each other.

E.g. Feet is in contact with th ground when walking

Which action involves pushing?

• pressing the doorbell

• raising a flag on a pole

• stretching a rubber band

• lifting books

Answer explanation

The other actions all involve pulling actions.

A push or pull is a ____.

Which of the following is NOT a force?

• frictional

• magnetic

• heat

• gravitational

A spring has ___ forces when it is stretched and compressed.

• magnetic

• elastic

• frictional

• gravitational

Friction occurs when two surfaces rub against one another.

• True

• False

Which of the following is an effect of friction?

• It does not affect the speed of object

• It speeds up a moving object

• It is similar to gravitational force which attracts object with mass

• It slows down or stops a moving object

When a force is applied, which of the following will NOT occur?

• change the speed

• change the shape

• change the mass

• change the size

Answer explanation

When a force is applied, the mass remains the same.

E.g. If a piece of a apple is cut into smaller pieces, the total mass of all the cut apples will still remain the same.

The unit to measure force is _.

Which equipment is used to measure force?

• electronic balance

• spring balance

• beam balance

• weighing scale