Q

Water strikes a wall normally at 10 m/s with a volume flow rate of 0.0001 m³/s. What force does it exert if its normal velocity becomes zero?

RRB Group-D 31/10/2018 / Shift III 2018
✓ Answer: A 1 N
F = ρQv = 1000 × 0.0001 × 10 = 1 N, using water density 1000 kg/m³. This follows from momentum flow; the source incorrectly introduces gravitational acceleration.