Chemical energy stores include: fuels, food or chemicals found in batteries. The energy is transferred during chemical reactions. Kinetic energy stores describe the energy an object has because it is moving. Gravitational potential energy stores are used to describe the energy stores in an object because of its position, such as an object above ground. Elastic potential energy stores describe the energy stored in a springy object when you stretch it or squash it. Thermal energy stores describe the energy a substance has because of its temperature.
1a. when a ball falls in the air, the gravitational textual energy decreasing then the kinetic energy increases and the there is a sound when the ball hits the ground. 1b. when an electrical heater switched on there is sound energy and thermal when it is switched on. 2a. candle torch 2b. candle is easier to obtain energy from and the torch is easier to use. 3a.