A metal ball of mass 60 g falls on a concrete floor from a vertical height of2.8m and rebounds to a height of 1.3 m. Find the change in K.E. in S.I. units

To find the change in kinetic energy, we first need to find the initial and final kinetic energy.

1. First, we need to convert the mass of the ball into kilograms (since we are asked to find the answer in SI units). So, 60 g = 0.06 kg.

2. The initial kinetic energy (just before the ball hits the floor) can be found using the equation for gravitational potential energy, which is mgh (mass x gravity x height). Here, m = 0.06 kg, g = 9.8 m/s² (acceleration due to gravity), and h = 2.8 m. So, the initial kinetic energy = 0.06 kg * 9.8 m/s² * 2.8 m = 1.64 Joules.

3. The final kinetic energy (just before the ball reaches its maximum height after rebounding) can also be found using the equation for gravitational potential energy. Here, m = 0.06 kg, g = 9.8 m/s², and h = 1.3 m. So, the final kinetic energy = 0.06 kg * 9.8 m/s² * 1.3 m = 0.764 Joules.

4. The change in kinetic energy is the initial kinetic energy minus the final kinetic energy. So, the change in kinetic energy = 1.64 Joules - 0.764 Joules = 0.876 Joules.