A water spray gun is attached to a hose of cross sectional area 30 cm2. The gun comprises of 10 perforations each of cross sectional area of 15 mm2. If the water flows in the hose with the speed of 50 cm/s, calculate the speed at which the water flows out from each perforation. (Neglect any edge effects)
- 100 m/s
- 10 m/s
- 1000 m/s
- 15 102 m/s
Answer
(2) 10 m/s
Solution
Hose: A1=30 cm2=30 10-4 m2, v1=50 cm/s =0.5 m/s
Total area of the perforations =10 15 mm2=150 10-6 m2
Equation of continuity: A1v1=(10a) v2
v2= 30 10-4 0.5150 10-6
v2= 1.5 10-31.5 10-4=10 m/s
Answer: (2)