B) moves with a constant speed until hitting the other end.
Explanation:
P= rho×g × h (g=10 m/s²) ,
(rho=1000 kg/m³)
P= 1000×10×5= 50,000 N/m² (C)
It’s to push an object in it’s direction of where it’s leading to.

why momentum is a property of moving objects, but not of stationary objects?
Answer:
Hi, There!-
Momentum is a property of a moving object because velocity is needed to get the momentum. Only a moving object has velocity.
Hope this Helps!

Final velocity = Initial velocity – 9.8 * t
Final velocity = 80.5 – 9.8 * 0.0124 = 80.378 m/s
OR
Final velocity = 80.5 – 9.8 * 16.416 = 80.378 m/s
A. -32 m/s
B. -97 m/s
C. -64 m/s
D. -81 m/s
E. -48 m/s