We have a box which is adiabatic and closed. Pressure outside of box is constant at P. Inside this box, water at 25 ℃ is contained in a cup located at the bottom of box. A lead ball with mass m and temperature of 25 ℃ is initially at a height of h in this box. The lead ball falls down to the bottom of box. After this event, what might be the final temperature of water and the lead ball?
In this example, the potential energy is converted to other form, increasing the energy of the system