Question

A ball of mass 2.0 kg falls vertically downward. Just before hitting the floor its speed is 30 m/s. Just after rebounding upward its speed is 21 m/s. If this change in velocity took place in a time of 0.10 seconds, what is the average net force on the ball

Answer 1

Answer:

The average net force on the ball is 1020 N.

Explanation:

Given that,

Mass of the ball, m = 2 kg

Its initial speed, u = 30 m/s

Just after rebounding upward its speed is 21 m/s, v = -21 m/s (direction is opposite of the initial direction)

If this change in velocity took place in a time of 0.10 seconds, t = 0.1 s

We need to find the net force on the ball. The net force is given by the product of mass and its acceleration as:

$F=ma$

a is acceleration of the ball

$F=\dfrac{m(v-u)}{t}\\\\F=\dfrac{2\times ((-21)-30)}{0.1}\\\\F=-1020\ N$

So, the average net force on the ball is 1020 N. Hence, this is the required solution.