Question

A 50kg obect falling through the air experiences a drag force of 90N. The acceleration of gravity is `9.8m/s^2`. What is the magnitude of the net force on the mass?

Answer 1

`400"N"`

Explanation:

The weight of the object acting downwards `= 50"gN"=490"N"`

The drag which acts in the opposite direction `=90"N"`

So the net force `=490-90=400"N"`

At the point where the weight equals the drag, there is no net force acting on the object. Since Force = mass x acceleration the acceleration is zero and the object moves at constant velocity.

This is known as "terminal velocity".