Forces and acceleration

Force, Mass and Acceleration

We know that the harder we push an object, the quicker it will accelerate. Therefore the greater the force we apply, the greater the acceleration of the object. 

The acceleration of the object and the force are said to be directly proportional to each other, (as one increases, the other increases at the same rate). 

This can be written as:

Equally, larger objects with more mass need a greater force to accelerate them. In this case the acceleration and the mass are inversely proportional to each other, (as one increases, the other decreases at the same rate). 

This is written as:

If we work with standard units, we can combine these into a single equation to give us:

F = mass x acceleration

As the force increases, the acceleration increases, but as the mass increases the acceleration will decrease.

We see this in action when a car brakes:

• Larger brakes leads to a larger force so the car stops more quickly, (the negative acceleration is greater)
• Larger vehicle has a larger mass so the car takes longer to stop, (the negative acceleration is reduced).

Finding Acceleration

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