(a)
consider the motion of the tennis ball. lets assume the velocity of the tennis ball going towards the racket as positive and velocity of tennis ball going away from the racket as negative.
m = mass of the tennis ball = 60 g = 0.060 kg
v₀ = initial velocity of the tennis ball before being hit by racket = 20 m/s
v = final velocity of the tennis ball after being hit by racket = - 39 m/s
ΔP = change in momentum of the ball
change in momentum of the ball is given as
ΔP = m (v - v₀)
inserting the above values
ΔP = (0.060) (- 39 - 20)
ΔP = - 3.54 kgm/s
hence , magnitude of change in momentum : 3.54 kgm/s
We don't even need to know how many pulses were produced
in those 3 seconds.
The beginning of the first pulse took 3 seconds to travel
45 centimeters from the generator.
Its speed is (45 cm) / (3 sec) = 15 cm/sec.
Answer:
he performed 100 push-ups, 100 sit-ups, and 100 squats, and ran 10 kilometers each day for over a year.
Explanation:
crazy right
