Answer:
18.33 Ns
Explanation:
As the pitch back speed has the opposite direction as before, the change in velocity would be

So the change in momentum of the ball would be the product of its velocity change and its mass

This is equals to the impulse acted on the ball by the bat, which is 18.33 Ns
Ground water keept the ground at a stable level when it is gone the cavern it was in has no support and is at risk of callaps
Answer:
884Hz
Explanation:
Beats is the absolute difference between two frequencies therefore
Beats = f1-f2
4=f1-880
F1=880+4
F1=884Hz
Time = (distance) / (speed)
= (30 km) / (30 m/s)
= (30,000 m) / (30 m/s)
= (30,000 / 30) sec
= 1,000 seconds
= 16 minutes 40 seconds