Determine the velocity of a body of mass $100g$ having a kinetic energy of $20J$.

Step 1: Given data:

Mass $m=100g$

$m=\frac{100}{1000}\Rightarrow 0.1kg$ $($As $1kg=1000g)$

Kinetic energy $KE=20J$

Step 2: Find the velocity with kinetic energy and mass:

Kinetic energy is given by,

$KE=\frac{1}{2}m{v}^2$

Where $m$ is mass, $KE$ is kinetic energy and $v$ is velocity. So,

$v^2=\frac{2\times KE}{m}$

$v=\sqrt{\frac{2\times KE}{m}}$

$v=\sqrt{\frac{2\times 20}{0.1}}$

$v=\sqrt{\frac{40}{0.1}}$

$v=\sqrt{400}$

$v=20m/s$

Therefore, the the velocity of a body of mass $100g$ having a kinetic energy of $20J$ is $20m/s$.