Question

The mass of the rock is 0.60 kg and it travels with a kinetic energy of 6500 J. find out the speed at which the rock travels. *

Answer 1

Given:

The mass of the rock is 0.60 kg and it travels with a kinetic energy of 6500 J.

To find:

Speed of rock ?

Calculation:

• Kinetic Energy is a sub-type of Mechanical Energy possessed by an object by the virtue of its motion.

• General expression of kinetic energy is :

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

• Putting all values in SI unit and let speed be 'v'.

$\implies 6500 = \dfrac{1}{2} \times 0.60 \times {v}^{2}$

$\implies 6500 = 0.30 \times {v}^{2}$

$\implies {v}^{2} = \dfrac{6500}{0.3}$

$\implies {v}^{2} = 21666.67$

$\implies v = \sqrt{21666.67}$

$\implies v = 147.19 \: m {s}^{ - 1}$

So, speed of rock is 147.19 m/s .