A stream of water flowing horizontally with a speed of 15 ms-1 gushes

1.	A stream of water flowing horizontally with a speed of 15 ms-1 gushes out of a tube of cross-sectional area 10-2 m2 and hits a vertical wall nearby. What is the force exerted on the wall by the Impact of water, assuming It does not rebound?
Answer» The volume of water hitting the wall per second = (Area × Velocity) of a stream of water = 10^-2 × 15 = 0.15 m³s^-1 density of water = 1000 kg/m³ ∴ mass of water hitting the wall per second = 0.15 × 1000= 150 kg/s Initial momentum of water hitting the wall per second = 150 × 15 = 250 kg m/s² or 2250 N Final momentum per second = 0 ∴ Force exerted on the wall: change in momentum per second = 2250 N.

A stream of water flowing horizontally with a speed of 15 ms-1 gushes out of a tube of cross-sectional area 10-2 m2 and hits a vertical wall nearby. What is the force exerted on the wall by the Impact of water, assuming It does not rebound?

Answer»

The volume of water hitting the wall per second

= (Area × Velocity) of a stream of water

= 10^-2 × 15

= 0.15 m³s^-1

density of water = 1000 kg/m³

∴ mass of water hitting the wall per second

= 0.15 × 1000= 150 kg/s

Initial momentum of water hitting the wall per second

= 150 × 15

= 250 kg m/s² or 2250 N

Final momentum per second = 0

∴ Force exerted on the wall: change in momentum per second

= 2250 N.