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FLUID MECHANICS - CASE STUDY

    Introduction


Firefighting Drill
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In a firefighting drill, a trainee learns to operate a fire hose. How much force should the trainee apply to hold the hose in a steady position? A nozzle is attached to the end of the hose to increase the velocity of the water. The nozzle outlet has a diameter of 3 in and the hose diameter is 6 in. The gage pressure at section 1 is 0.75 psi, and the water flows at a rate of 0.5 slugs/s. The length of the pipe is 2 ft.

   
  Questions

  Find the required force to keep the hose in place.
     

Problem Description
  Approach

 
  • Choose an appropriate control volume, and label all forces and velocities.
  • Apply the linear momentum equation.
  • Neglect the weight of the hose, nozzle and water inside the nozzle.
  • The density of the water is 1.94 slugs/ft3.