Question

A player caught a cricket ball of mass 150 g moving at a rate of 20 m/s. The catching process is completed in 0.1 second. What is the force exerted by the ball on the hand of the player?
A.15 N
B.20 N
C.30 N
D.40 N

Answer 1

The given problem is the problem related to the impulse and this is governed by Newton's second law of motion. According to Newton's second law of the motion, if a body is going under impulsive force then the force acting on the body will be equal to the rate of change of the momentum of the body.

Complete answer:
Here given,
Mass of the moving ball= 150g = 0.15Kg
Initial velocity of the ball= $u = 20$m/s
When the ball will reach to the hand of the player then the final velocity of the ball = $v = 0$m/s
Change in the time is = $\Delta t = 0.1\sec$
So, we have the formula for the force in this case,
$F = \dfrac{{\Delta p}}{{\Delta t}}$, where $\Delta p =$change in the momentum, $\Delta t =$change in the time.
$\Rightarrow F = \dfrac{{m(u - v)}}{{\Delta t}}$
Now putting all the values, we get
$\Rightarrow F = \dfrac{{0.15(0 - 20)}}{{0.1}}$
$\Rightarrow F = \dfrac{{ - (0.15 \times 20)}}{{0.1}}$
$\Rightarrow F = - 30N$
So, the magnitude of the force is 30N and the direction will be opposite to the direction of the previous motion of the ball.
Hence, the force exerted by the ball on the hand of the player is 30 N.

So, option (C) is the correct answer.

Additional information:
More specifically, Newton's first law of laws of motion describes the force qualitatively, the second law gives a measurable estimate of the force, and the third law states that there is no single independent force. The first law states that if the total force is zero (the vector sum of all forces acting on an object), then the object's velocity is constant. Velocity is a quantity of vectors that represents both the velocity of the object and the direction of its motion; thus, the assertion that the velocity of the object is constant is a declaration that both its velocity and the direction of its motion are unchanged.

Note:
Newton's motion laws are three physical laws which together laid the foundations for classical mechanics. We define the interaction between a body and its forces and its action in reaction to those forces. In order to solve such types of problems, students must remember all the three laws of motion and formula associated with it.