Falling Body Problems:

1. A ball with mass 0.1 kg is thrown upward with an initial velocity 20 m/s from the roof of a building 25 m high. Neglect air resistance.

 (a) Find the maximum height above the ground that the ball reaches.
 (b) Find the time that it hits the ground assuming the ball misses the building on its way down.

     solution

2. A 10 kg object is shot straight up with an initial velocity of 10 m/s from a cliff that is 60 meters high. If air resistance is given by 2|v|, determine the velocity of the object when it hits the ground.

solution (upward direction +ve)

3. A 5 kg object is shot straight up with an initial velocity of 10 m/s off a cliff  that is 40 meters high. If air resistance is given by 2|v|, determine the maximum height the object reaches.

solution (upward direction +ve)

4. A sky diver weighing 180 lb (including equipment) falls vertically downward from an altitude of 8000 feet and opens the parachute after 15 seconds of free fall. Assume that the force of air resistance is \(0.8|v|\) when the parachute is closed and \( 10|v|\) when the parachute is open, where \(v\) is measured in ft/sec.

 (a) Find the speed of the sky diver when the parachute opens.
 (b) Find the distance fallen before the parachute opens.
 (c) What is the limiting velocity, \(v_L\) after the parachute opens?
 (d) Determine how long the sky diver is in the air after the parachute opens.

   solution