Final answer:
When a parachutist opens his parachute, his kinetic energy is converted into potential energy and dissipated as heat due to air resistance.
Step-by-step explanation:
When a parachutist opens his parachute, his kinetic energy decreases. This is because the parachute creates air resistance, which opposes the parachutist's motion. As a result, the kinetic energy of the parachutist is converted into other forms of energy, primarily potential energy and heat.
The potential energy of the parachutist increases as the altitude decreases. This is because the parachutist is moving against the pull of gravity, and the potential energy depends on the height above the ground. So, the parachutist's kinetic energy is converted into potential energy.
In addition, some of the kinetic energy is dissipated as heat due to air resistance. As the parachute opens, it creates drag, and this drag generates heat. Therefore, a portion of the kinetic energy is transformed into heat energy.
Thus, the correct answer is a) It is converted into potential energy and b) It is dissipated as heat.