Question

A 2-kg object is dropped from a height of 1000 m. What is the force of air resistance on the object when it reaches terminal velocity?

Answer 1

`19.6"N"`

Explanation:

The falling object experiences its weight acting downwards and the air resistance in the opposite direction.

The air resistance increases with velocity so there may come a point, depending on the shape of the object and if there is sufficient height, where these 2 forces are equal.

Since the object has no net forces acting on it it will, according to Newton, no longer accelerate but continue with a constant velocity.

This is called Terminal Velocity.

So:

Air resistance = weight

`R=mg`

`:.R=2xx9.8=19.6"N"`

In the graphic you can see that the large air resistance of the parachute is balanced by her weight. She floats to the ground at a constant, terminal, velocity.