Concepts of Physics

IIT JEE Physics (1978-2018: 41 Years) Topic-wise Complete Solutions

Conversion of Kinetic Energy into the Heat


To study transformation of the energy.


a conical flask with rubber stopper, dry sand, thermometer


Take sand in the flask. Introduce the thermometer into the sand and measure its temperature. Take out thermometer and close the mouth of the flask with the stopper. Shake the flask for a few minutes. Open the stopper and introduce the thermometer into the sand again and measure the temperature. You will observe that the temperature has increased.


When the flask is shaken, the sand gets kinetic energy. The sand particles rub against one another when the flask is shaken. The temperature of the sand increases because of friction. When the flask is shaken the mechanical energy is converted into heat energy.