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A player receives a shot with the ball (0.06 kg) traveling horizontally at 50 m/s and returns the shot at 40 m/s in the opposite direction.

a) What is the impulse delivered to the ball by the racket?
b) What work does the racket do on the ball?
a) -3 kgm/s, 0 J
b) 3 kgm/s, 2500 J
c) -3 kgm/s, 3000 J
d) 3 kgm/s, 3000 J

User Ashley Bye
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1 Answer

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Final answer:

The impulse delivered to the ball by the racket is -5.4 kg·m/s, and the work done by the racket on the ball is -27 J. None of the answer choices provided in the question are correct.

Step-by-step explanation:

The impulse delivered to the ball by the racket can be calculated as follows:

  • Impulse (J) = Change in momentum = final momentum - initial momentum.
  • Initial momentum = mass × initial velocity = 0.06 kg × 50 m/s = 3 kg·m/s (positive since it's to the right).
  • Final momentum = mass × final velocity = 0.06 kg × (-40 m/s) = -2.4 kg·m/s (negative since it's to the left).
  • Change in momentum = -2.4 kg·m/s - 3 kg·m/s = -5.4 kg·m/s.
  • Thus, the impulse delivered to the ball by the racket is -5.4 kg·m/s.

To calculate the work done by the racket on the ball:

  • Work (W) = Change in kinetic energy = final kinetic energy - initial kinetic energy.
  • Initial kinetic energy = 0.5 × mass × (initial velocity)^2 = 0.5 × 0.06 kg × (50 m/s)^2 = 75 J.
  • Final kinetic energy = 0.5 × mass × (final velocity)^2 = 0.5 × 0.06 kg × (40 m/s)^2 = 48 J.
  • Change in kinetic energy = 48 J - 75 J = -27 J.
  • The work done by the racket on the ball is -27 J, which means the ball has lost 27 J of energy.

Since none of the provided answer choices match these calculations, the correct response is that none of the answer choices are correct.

User Mohammed Mustafa
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7.9k points