EVERYDAY SCIENCE

Detailed explanation-1: -So when the quarterback is about to throw the football, or the kicker is about to kick the football, there is 100% of gravitational potential energy. Once the football is thrown we will say 80% of the gravitational potential energy is kinetic energy and 20% is heat energy.

Detailed explanation-2: -When a ball is thrown, initially it has only kinetic energy. When it reaches a maximum height all the kinetic energy is converted into potential energy. Mid-way, the ball has equal potential and kinetic energy. When the ball just touches the ground it only has kinetic energy.

Detailed explanation-3: -Each player in a tackle has their own kinetic energy. It has been calculated that the energy in a collision between two football players could lift 23 tons of concrete an inch into the air. Such energy can cause severe injuries and damage to the body of the football player.

Detailed explanation-4: -The football has 32 joules of potential energy due to its position above the ground. It also has 45 joules of kinetic energy due to its motion. The total mechanical energy of the football is 32 joules + 45 joules, or 77 joules.