Question

two identical balls each of mass 2 kg are moving towards each other with the same speed of 5 M per second they collide with each other stick together and come to rest what is the work done by the internal forces

Answer 1

Mass of each ball = 2 kg

Speed of each ball = 5 m/s

Work done by the internal forces will be equal to the change in the kinetic energy of the each ball.

Since, each ball is coming to rest. Hence, the final kinetic energy is zero.

Initial kinetic energy of each ball = $\frac{1}{2} \times m \times v^2$

Initial kinetic energy of each ball = $\frac{1}{2} \times 2 \times 5^2$

Initial kinetic energy of each ball = 25 Joules

Total kinetic energy of the system = 2 × 25 = 50 Joules

Work done by the internal forces = Change in the kinetic energy

Work done by the internal forces = 0 - 50

Work done by the internal forces = - 50 Joules

Answer 2

Answer:

-50 Joules

answer is given in the attachment