Loading please wait

The smart way to improve grades

Comprehensive & curriculum aligned

Try an activity or get started for free

Balanced and Unbalanced Forces

In this worksheet, students will explore the question 'how do forces affect speed?'

'Balanced and Unbalanced Forces' worksheet

Key stage:  KS 3

Curriculum topic:   Physics: Motion and Forces

Curriculum subtopic:   Motion and Forces

Difficulty level:  

Worksheet Overview

For an object to move, the forces on it must be unbalanced.

 

In the diagram below, the duck is floating on the water. It is not moving up or down because the force acting downwards (caused by gravity) is equal to the force of the water pushing up on to the duck (upthrust).

 

Duck  Up and down arrows

The force of gravity (red arrow) is equal to the upthrust (green arrow) from the water.

 

The car shown below is accelerating because the driving force (green arrow) is greater than the drag caused by air resistance (red arrow).

 

Car

 

The car is accelerating left to right because the driving force is greater than the air resistance

 

When the drag is greater than the driving force, the car will slow down; but if they are balanced and the car is already moving, it will continue to move at a constant speed. This is described in more detail in Isaac Newton's 'Laws of Motion'.

 

There are many forces acting on a skydiver when they leave the plane:

 

Skydiver

 

As a skydiver leaves the plane, they accelerate downwards due to gravity, but as their speed increases, so does the air resistance. This continues until both forces are balanced and the skydiver will fall at a constant speed, called their terminal velocity. 

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
laptop

Try an activity or get started for free

  • educational
  • bettfutures
  • cxa
  • pta
  • era2016
  • BDA award
  • Explore LearningTuition Partner
  • tacm