Question

An engine can pump 40,0000 liter of water to vertical height of 35 meters in 5 minutes. Calculate gravitational potential energy of water at given height.

• A. $1.37\times {10}^7$J
• B. $1.37\times {10}^8$J
• C. $13.7\times {10}^7$J
• D. $7\times {10}^7$J

Answer 1

The correct option is A $1.37\times {10}^7$J

$W=mgh$

$=(\rho \times V)gh$

$={10}^3\times 4000000\times {10}^{-3}\times 9.8\times 35J$

$=4\times 9.8\times 35\times {10}^{5}J$

$=137\times {10}^{5}J$

$=1.37\times {10}^{7}J$