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A. What is the momentum of an 8-kg bowling ball rolling at 2 m/s?

b. If the bowling ball rolls into a pillow and stops in 0.5 s, calculate the average force it exerts on the pillow.
c. What average force does the pillow exert on
the ball?

2 Answers

6 votes

Final answer:

a. The momentum of the bowling ball is 16 kg·m/s. b. The average force exerted by the bowling ball on the pillow is 32 N. c. The average force exerted by the pillow on the ball is also 32 N.

Step-by-step explanation:

a. To calculate the momentum of the bowling ball, we can use the formula momentum = mass x velocity. In this case, the mass of the bowling ball is 8 kg and its velocity is 2 m/s. Therefore, the momentum of the bowling ball is 8 kg x 2 m/s = 16 kg·m/s.

b. To calculate the average force exerted by the bowling ball on the pillow, we can use the formula average force = change in momentum / time. The change in momentum is the initial momentum of the bowling ball (16 kg·m/s) minus its final momentum (which is 0 because it stops) and the time is given as 0.5 s. Therefore, the average force exerted by the bowling ball on the pillow is (16 kg·m/s - 0 kg·m/s) / 0.5 s = 32 N.

c. The pillow exerts an equal and opposite force on the bowling ball according to Newton's third law of motion. Therefore, the average force exerted by the pillow on the ball is also 32 N.

User Carlosvini
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3 votes

Answer:

a. 16 kg m/s

b. -32 N (Newton)

c. 32 N

Step-by-step explanation:

a. The momentum of an object is the product of its mass and velocity. The formula for momentum is: momentum = mass x velocity

So, in the case of an 8-kg bowling ball rolling at 2 m/s, the momentum would be: momentum = 8 kg x 2 m/s

= 16 kg m/s

The unit of momentum is kg m/s (kilogram meter per second). The momentum of this bowling ball is 16 kg m/s. It is important to note that the direction of velocity is also important when calculating momentum, so it is important to know the direction of the bowling ball.

b. To calculate the average force that the bowling ball exerts on the pillow, we can use the equation: force = change in momentum / change in time

The change in momentum is equal to the final momentum minus the initial momentum. Since the bowling ball is rolling at 2 m/s and stops in 0.5s, we can assume that its final momentum is 0 (since it stops moving) and the initial momentum is 16 kg m/s.

change in momentum = final momentum - initial momentum

= 0 - 16 kg m/s

= -16 kg m/s

change in time = 0.5s

So,

force = -16 kg m/s / 0.5 s

= -32 N (Newton)

The negative sign indicates that the force is opposite to the direction of motion of the bowling ball. This is expected as the force exerted by the pillow is acting in the opposite direction of the ball's motion, thus slowing it down and bringing it to a stop.

It is important to note that the force exerted by the pillow on the bowling ball is equal and opposite to the force exerted by the bowling ball on the pillow, this is Newton's third law of motion.

c. The average force that the pillow exerts on the ball is equal and opposite to the average force that the ball exerts on the pillow, as stated by Newton's third law of motion. This is because when the ball collides with the pillow, the pillow exerts an equal and opposite force on the ball to stop its motion. Therefore, the average force that the pillow exerts on the ball is 32 N, in the opposite direction of the ball's motion.

User Nate Abele
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7.8k points