Question

cricket ball of mass 100 g moving with a

speed of
30 m/s is brought to rest by a player in 0.03
5. Find
a. the change in momentum of the ball.
b. the average force applied by the player.


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Answer 1

Given:-

• A player brough a moving ball to rest by applying a force.
• mass of ball, m = 100 g = 0.1 kg
• Initial velocity of cricket ball, u = 30 m/s
• Final velocity of ball, v = 0 m/s
• time taken for change in velocity, t = 0.03 s

To find:-

• Change in the momentum of the ball, Δp =?
• The average force applied by the player, F =?

The formula required:-

• Formula for change in momentum

        Δp = ( Final p) - (Initial p) = mv - mu

Formula to calculate force

•         F = Δp / t

• [ Where p is momentum, m is mass, v is final velocity, u is initial velocity, F is force and t is the time ]

Solution:-

Calculating the change in momentum of the ball

• → Δp = mv - mu
• → Δp = (0.1 × 0) - (0.1 × 30)
• → Δp = -3 kg m/s

Now, calculating the force applied by the player

• → F = Δp / t
• → F = -3 / 0.03
• → F = -100 N

Therefore,

• There is a change of -3 kg m/s in the momentum of the ball. (negative sign represents that momentum of the ball decreased with the time)

• and, A force of magnitude 100 N was applied by the Player against the direction of motion of the ball.

Answer 2

Answer:

the change in momentum of the ball.