A water jet with a cross-sectional area of 4.0 × 10-4 m2 strikes a vertical wall horizontally at a constant speed of 15 m s-1. Upon hitting the wall, the water loses all its horizontal velocity and flows downwards.
The density of water is 1000 kg m-3.
What is the horizontal force exerted by the water on the wall?
6.0 N6.0\text{ N}6.0 N
45 N45\text{ N}45 N
90 N90\text{ N}90 N
180 N180\text{ N}180 N