Author Question: A soccer ball (mass = 0.43 kg) is moving at a speed of 20 m/s when it is kicked with a force of 300 ... (Read 98 times)

frankwu · **on:** Jul 28, 2018

A soccer ball (mass = 0.43 kg) is moving at a speed of 20 m/s when it is kicked with a force of 300 N resulting in it going in the opposite direction with the same speed as before. What is the magnitude of the impulse delivered to the ball?
a. 0, because the before and after momenta cancel each other.
b. 8.6 kgm/s
c. 17 kgm/s
d. 2600 kgm/s

Question 2

A ping-pong ball covered with a conducting graphite coating has a mass of 2.5 10-3 kg and a charge of 4.0 C. What electric field directed upward will exactly balance the weight of the ball? (g = 9.8 m/s2)
a. 6.1 103 N/C
c. 5.1 106 N/C
b. 2.0 10-7 N/C
d. 1.2 104 N/C