Describe the interconversions of forms of energy occurring in these processes: (a) You throw a softball up into the air and catch it. (b) You switch on a flashlight. (c) You ride the ski lift to the top of the hill and then ski down. (d) You strike a match and let it burn down.

Energy comes in different forms: kinetic, potential, thermal, light, chemical, mechanical, electrical, etc. Understanding the scenario and applying these concepts, we can identify the initial and final types of energy.

(a) In the case of throwing a softball into the air, initially you use mechanical energy. As the ball is thrown up, it gains gravitational potential energy. When the ball reaches its highest point and falls back down, the potential energy is converted to kinetic energy. (b) For the flashlight, we have chemical energy stored in the batteries. When it is switched on, this chemical energy is converted to electrical energy, which is then converted to light and a bit of thermal energy. (c) Riding the ski lift is a conversion from electrical energy (used to run the lift) to gravitational potential energy (as you are lifted to a higher elevation). Skiing down converts this potential energy back to kinetic energy. (d) When striking a match, the initial energy is chemical (stored in the match). Upon striking, it is converted to thermal (heat) and light energy.

In summary, these are the transformations: (a) Mechanical to kinetic and potential energy. (b) Chemical to electrical to light and thermal energy. (c) Electrical to potential to kinetic energy. (d) Chemical to thermal and light energy. Understanding the conversion of energy forms is key to understanding many processes in physics.