Work Energy And Power Question 190
Question: A 10 H.P. motor pumps out water from a well of depth 20m and fills a water tank of volume 22380 litres at a height of 10m from the ground. the running time of the motor to fill the empty water tank is $ (g=10m{s^{-2}} $ ) [EAMCET (Engg.) 2000]
Options:
A) 5 minutes
B) 10 minutes
C) 15 minutes
D) 20 minutes
Show Answer
Answer:
Correct Answer: C
Solution:
Volume of water to raise = 22380 l = 22380×10?3m3
$ P=\frac{mgh}{t}=\frac{V\rho gh}{t} $
therefore $ t=\frac{V\rho gh}{P} $
$t =\frac{22380\times {10^{-3}}\times 10^{3}\times 10\times 10}{10\times 746}=15 $ min
