Exam-style question
Try this first
A car is accelerating to the right. Draw a free-body diagram showing the forces acting on the car. Include labels for each force.
Model answer
What a good answer should say
- The free-body diagram should show the driving force acting to the right, the frictional force acting to the left, the weight of the car acting downwards, and the normal force acting upwards.
- The driving force must be greater than the frictional force for the car to accelerate.
Explanation
Why this works
This question assesses the ability to identify and represent forces acting on a moving object. The evidence indicates that the net force is directed to the right, which implies that the car is accelerating.
The conclusion is that the unbalanced forces result in the car's acceleration according to Newton's second law.
Common mistake
No common mistake is linked to this question yet.