A 7.0kg skydiver is descending with a constant velocity

The air resistance on the skydiver is 68.6 N

Explanation:

When the skydiver is falling down, there are two forces acting on him:

- The force of gravity, of magnitude , in the downward direction (where m is the mass of the skydiver and g is the acceleration due to gravity)

- The air resistance, , in the upward direction

So the net force on the skydiver is:

where

m = 7.0 kg is the mass

According to Newton's second law of motion, the net force on a body is equal to the product between its mass and its acceleration (a):

In this problem, however, the skydiver is moving with constant velocity, so his acceleration is zero:

Therefore the net force is zero:

And so, we have:

And so we can find the magnitude of the air resistance, which is equal to the force of gravity:

305.7

explanation:

density =m/v

density =917/3.00

density = 305.

approximately = 305.7

in four significant figures