Impulse = Change in momentum.
The ball was moving with a momentum of 0.45 * 22 = 9.9
The ball comes to rest in the receivers arm; this means the ball's final velocity = 0. So mv2 = 0.45 * 0
The magnitude of the impact is just the change in momentum. 9.9 - (0.45 * 0) = 9.9
Speed
= (distance covered) / (time to cover the distance)
= (25 m) / (5.0 sec) = 5.0 m/s .
Answer:
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:
