How are mass, force and acceleration related?

Two masses of 1 kg and 4 kg are both subject to the same force, which one will accelerate the fastest?

The lower the mass, the greater the acceleration for a specific force. This is why Grand Prix cars get faster as they use up their fuel. Less fuel, means less mass, less mass means greater acceleration.

F=ma

We can express the relationship between force, mass and acceleration using the equation:

Force = mass x acceleration

F =ma

Force measured in Newtons (N)

Mass measured in kilograms (kg)

Acceleration measured in metres per second per second (ms-2)

Formula triangles

F

m a

x

Formula triangles help you to rearrange formula. The triangle for the f=ma formula is shown below:

Whatever quantity you are trying to find, cover it up and it will leave you with the calculation required.

So if you were trying to find mass, m…..

…you would cover m up…

…and you are left with the sum…

m = F

a

Force calculations:

1. What force will make a mass of 4 kg accelerate at 5 ms-2?

2. A force of 50N acts on a 2 kg mass. What will be the acceleration of the mass?

3. A force of 2 000N accelerates a car at 2.5 ms-2. What is the mass of the car?

Force = 20 N

Acceleration = 25 ms-2

Mass = 800 kg