Question #eae28

1 Answer
Aug 27, 2017

I get this.

Explanation:

The problem consists of sum of two pressures which the pump must create

  1. Pressure due to height of 40m of water column
  2. Pressure due to jet of water at a rate of 5ms1

For 1. Assuming unit area, Force=Pressure

Pressure due 40m water column P1=mg=ρ×volume×g
P1=1000×(40×1)×9.81=392400pa

For 2. Assumed area of the jet be unit area.
Speed of water outlet from jet =5ms1.
Total mass of water thrown out per sec=ρ×1×5=5000kg

Pump must exert pressure to support weight of this additional column of water of unit area=5000×g=49050N

For unit area of jet pressure P2=49050pa

Total pressure of the pumpP=P1+P2=392400+49050=441450pa