Question

A moving body of mass 0.3 kg has 60 J of kinetic energy. Calculate the speed of the body​

Answer 1

Answer:

speed =

$\sqrt{ \frac{2 \: kinectic \: energy}{mass} }$

=

$\sqrt{ \frac{2 \times 60}{0.3 } } = 20$ m/s

Answer 2

$\boxed{\displaystyle\sf{K.E.=\frac{1}{2}\:m\:v^2}}$

Where,

• K.E = kinetic energy of a body   = 60 J

• m = mass of the body   = 0.3 kg

• v = velocity of the body  = x m/s

Applying the values to the equation,

$\implies\displaystyle\sf{60=\frac{1}{2}\times0.3\times v^2}$

$\implies\displaystyle\sf{120=0.3\times v^2}$

$\implies\displaystyle\sf{v^2=\frac{120}{0.3}}$

$\implies\displaystyle\sf{v^2=400}$

$\implies\displaystyle\sf{v=20\:m/s}$

$\boxed{\displaystyle\sf{Velocity=20\:m/s}}$