Answer:
[tex]\boxed{\pink{\sf Velocity \ of \ the \ body \ is \ 30m/s .}}[/tex]
Explanation:
Given that a body is moving which has a mass of 100g. And its Kinetic energy is 45 Joules . We need to find its velocity . So ,
[tex]\boxed{\red{\bf Kinetic\: Energy =\dfrac{1}{2}mv^2 }}[/tex]
Now here mass is in grams. So converting it into SI units we have , 100/1000 kg = 0.1 kg
[tex]\implies KE =\dfrac{1}{2}mv^2 \\\\\implies 45 J = \dfrac{1}{2}\times \dfrac{1}{10} kg \times v^2 \\\\\implies v^2 = 45 \times 20 \\\\\implies v^2 = 900 m^2/s^2 \\\\\implies v =\sqrt{900 m^2/s^2} \\\\\underline{\boxed{\blue{\tt \implies Velocity = 30m/s }}}[/tex]