Question

A soccer ball with a mass of 0.434 kg approaches a player horizontally with a speed of 13.0 m/s. The player kicks the ball with her foot, which causes the ball to move in the opposite direction with a speed of 22.7 m/s.
(a) What magnitude of impulse (in kg · m/s) is delivered to the ball by the player? kg · m/s
(b) What is the direction of the impulse delivered to the ball by the player? Opposite to the ball's initial velocity In the same direction as the ball's initial velocity Perpendicular to the ball's initial velocity The magnitude is zero.
(c) If the player's foot is in contact with the ball for 0.0600 s, what is the magnitude of the average force (in N) exerted on the player's foot by the ball? N

Answer 1

Answer:

a) 15.49

b) Opposite to the ball's initial velocity

c) 258.16N

Explanation:

a)

$\Delta p=m \Delta v\\\\\Delta p= (0.434)(13.0-(-22.7)) \\\\\Delta p=(0.434)(35.7)\approx 15.49 kg \cdot m/s$

b)

Since the player is kicking the ball in the opposite direction to which it came, the impulse is being directed opposite to the ball's initial velocity.

c)

$\Delta p= F \Delta t \\\\\\F=\dfrac{\Delta p}{\Delta t} \\\\\\F=\dfrac{15.49 kg \cdot m/s}{0.06 s}\approx 258.16N$

Hope this helps!