# Compare Mass, Weight and Gravity

In this worksheet, students will learn about gravity and how mass is different to weight.

Key stage:  KS 3

Curriculum topic:   Physics: Space Physics

Curriculum subtopic:   Gravity Forces

Popular topics:   Space worksheets, Physics worksheets

Difficulty level:

#### Worksheet Overview

In this activity, we will be learning about mass and weight

When we get on the scales, we measure our mass.

Mass is the amount of matter which makes up an object or a living organism.

It is measured in grams (g) and kilograms (kg).

On Earth, gravity pulls every kilogram with a force of 10 N (Newtons).

If a person has a mass of 50 kg, their weight on Earth is 500 N. We get that by multiplying the mass (50 kg) by 10 N.

The weight of the same object or person changes according to the planet they are on! The mass though always stays the same. Got that?

Weight is the force of gravity pulling everything towards the centre of the Earth.

Gravity is everywhere: in water, in air and even if we stand on the ground, gravity still pulls us towards the centre of the Earth.

Luckily, there is a reaction force from the ground to counteract that!

Well, have a look at the diagram to see how gravity keeps the moon in orbit around the Earth.

Both the moon and the Earth attract each other by gravity.

The next diagram shows gravity as the red arrow pulling the book down.

The only reason the book is not falling through the table is the reaction force from the table acting in the opposite direction (shown in the upward arrow).

It all sounds rather complicated, so remember that you can look back at this introduction at any point by clicking on the red help button on the right of the question screen.

Let's try some questions.

### What is EdPlace?

We're your National Curriculum aligned online education content provider helping each child succeed in English, maths and science from year 1 to GCSE. With an EdPlace account you’ll be able to track and measure progress, helping each child achieve their best. We build confidence and attainment by personalising each child’s learning at a level that suits them.

Get started