Water flows out of a large reservoir through an open pipe,as shown in the figure.What is the speed of the water as it comes out of the pipe?
A)8.9 m/s
B)9.9 m/s
C)13 m/s
D)14 m/s
E)16 m/s

Question

Water flows out of a large reservoir through an open pipe,as shown in the figure.What is the speed of the water as it comes out of the pipe? 
A)8.9 m/s 
B)9.9 m/s 
C)13 m/s 
D)14 m/s 
E)16 m/s

Quizplus · Accepted Answer

From the Bernoulli's equation, we can write:

1/2ρv1^2 + ρgh1 = 1/2ρv2^2 + ρgh2

Where, 
ρ = Density of water 
v1 = Velocity of water at the top of the reservoir = 0 m/s
h1 = Height of water above the pipe = 75 m
v2 = Velocity of water at the exit of pipe = ?
h2 = Height of water at the exit of the pipe = 0 m (i.e., pipe is at ground level)

Assuming negligible frictional losses, we can neglect the pressure term in the Bernoulli's equation. Rearranging the above equation, we get:

v2 = √(2gh1)

Substituting the given values, we get:

v2 = √(2 x 9.81 m/s^2 x 75 m)

v2 = 13.05 m/s (approx.)

Therefore, the speed of water as it comes out of the pipe is approximately 13 m/s. Hence, the correct answer is choice C).

Water Flows Out of a Large Reservoir Through an Open