Question

A river of salty water is flowing with a velocity $2m/sec$. If the density of the water is $1.2gm/cc$., then the kinetic energy of each of cubic the meter of water is

• A. $2.4J$
• B. $24J$
• C. $4.8J$
• D. $2.4KJ$

Answer 1

The correct option is D $2.4KJ$

Given,

Water velocity, $v=2m/s$

Density of water, $\rho =1.2g/cc$

Therefore,

Mass of each cubic centimeter, $M=\frac{1.2\times {10}^{-3}}{({10}^{-2}{)}^3}=1.2\times {10}^{3}kg$

So,

Kinetic Energy, $K.E=\frac{1}{2}m{v}^2=\frac{1}{2}\times 1.2\times {10}^3\times 2^2=2400J=2.4KJ$