A ball whose mass is 0.4 kg hits the floor with a speed of 8 m/s and rebounds upward with a speed of 6 m/s. Collapse question part Part 1 (a) If the ball was in contact with the floor for 0.5 ms (0.5 × 10-3 s), what was the average magnitude of the force exerted on the ball by the floor?

The  the average magnitude of the force exerted on the ball by the floor N

Explanation:

Given:

Mass of ball kg

Initial speed

Rebound speed

Contact time interval sec

For finding the average magnitude of the force on the ball by the floor is given by,

Here

    N

Therefore, the  the average magnitude of the force exerted on the ball by the floor N

given data:

determine the horse power (h.p) = ?

force applied to move the box(f) = 10 pounds,

box lifted from a distance         (d) = 3 feet

time taken to lift                         (t) = 10 sec,

the horse power is defined as amount of work required to move a load. the horse power is equal to 550 foot-pound per second

                  1 h.p   = 550 foot-pound/second

it can also be defined as the the load that need to be move a body for certain distance in a certain amount of time.

mathematically,

                      h.p = (force × distance)/ time

                            = (10 × 3)/ 10

                            = 30/10

                            = 3 foot -pound/sec

hence, the horse power is needed to move the box is 3 foot-pound/second

important note: 1 h.p = 550 foot-pound/second = 746 watts

hey , the answer is c