1. Balanced and unbalanced forces
By the end of this presentation you should be able to…
Explain the difference between balanced and unbalanced forces with the use of examples.
Describe the effect of unbalanced forces on the speed of an object.
Explain what acceleration is.
Remember and use the equation F = m x a.
Thank you to W. Richards from Worthing High School, for the use of parts of his presentation.

2. Balanced and unbalanced forces
Reaction
Consider a camel standing on a road. What forces are acting on it?
What forces would be acting on any object that is resting on the ground, that is stationary?
These two forces would be equal – we say that they are BALANCED. The camel doesn’t move anywhere.
Weight

3. Balanced and unbalanced forces
Reaction
What would happen if we took the road away?
What would happen to the camel if there was no floor?
The camel’s weight is no longer balanced by anything.
…but his weight is still there! It is now UNBALANCED, so the camel falls downwards!
Weight

4. Balanced and unbalanced forces
1) This animal is either ________ or moving with _____ _____…
2) This animal is getting _________…
3) This animal is getting _______….
4) This animal is…

5. Balanced and unbalanced forces

6. Force and acceleration
Who will accelerate?
They BOTH will accelerate to the right!
How much they accelerate will depend on how heavy they are, and on the size of the forces they exert on each other.
So acceleration = unbalanced force / mass
This triangle gives us an easier way to remember the equation : F = ma
If the forces acting on an object are unbalanced then the object will accelerate, like these wrestlers: F a m
Force (in N) = Mass (in kg) x Acceleration (in m/s2)

7. Force, mass and acceleration
A force of 1000N is applied to push a mass of 500kg. How quickly does it accelerate?
A force of 3000N acts on a car to make it accelerate by 1.5m/s2. How heavy is the car?
A car accelerates at a rate of 5m/s2. If it weighs 500kg how much driving force is the engine applying?
A force of 10N is applied by a boy while lifting a 20kg mass. How much does it accelerate by? F a m