This is a suggested answer to the GCE O Level Pure Physics examination, year 2019, Paper 1, multiple choice question 8.

The question provided the following data on a car that is accelerating

- Mass of car is 800kg
- The car’s engine exerts a driving force of 2500N
- Acceleration of car is 2.0m/s
^{2}

The student is required to calculate the resistive force acting on the car.

## Suggested Solution:

The answer is A. That is, the resistive force is 900N.

## Explanation:

The Resultant force that resulted in the car accelerating is given by the formula:

Resultant Force, F = Mass x acceleration

F = 800kg x 2.0m/s^{2}

= 1600N

The Resultant force is actually the result of the force the car engine exerts (which is given as 2500N) and the resistive force.

Hence, the Resistive Force = 2500N-1600N

=900N