In sports, where does the $kinetic energy$ that people use to move primarily originate?

• A. It is produced by the $gravitational potential energy$ of the Earth acting on the body.
• B. It is generated directly from the $heat energy$ absorbed from the environment.
• C. It comes from the $chemical energy$ stored in food, which is converted by the body into $kinetic energy$.
• D. It is supplied by the $electrical energy$ from external sources such as batteries.

Answer: (C)

Verified step by step guidance

1. Understand that kinetic energy in the human body during movement comes from energy transformations within the body.
2. Recognize that the body obtains energy primarily from the chemical energy stored in food molecules, such as carbohydrates, fats, and proteins.
3. Know that through metabolic processes, the chemical energy in food is converted into usable forms of energy like ATP (adenosine triphosphate), which powers muscle contractions.
4. Realize that this chemical energy conversion is what ultimately produces the kinetic energy that allows muscles to move and perform work.
5. Conclude that the kinetic energy used in sports originates from the chemical energy stored in food, not from gravitational potential energy, heat energy from the environment, or electrical energy from external sources.