Kinetic Energy

Kinetic energy is defined as the energy an object possesses due to its motion. The word kinetic comes from the Greek kinesis, meaning movement.

The definition directly matches: 'The energy an object has due to its motion.' Any object that is moving — whether a football, a car, or a molecule — has kinetic energy.

The correct answer is 'The energy an object has due to its motion.' The other options describe different forms of energy: position (gravitational potential energy), chemical bonds (chemical energy), or total energy (a different concept entirely).

The question asks for the definition of kinetic energy. We need to find the option that correctly describes what kinetic energy is.

'The energy an object has due to its position above the ground' describes gravitational potential energy, not kinetic energy. Eliminate this option.

'The energy stored in chemical bonds within an object' describes chemical energy (e.g., energy in food or fuel). This is not kinetic energy. Eliminate this option.

'The total energy an object can ever possess' is not a standard definition of any single energy type and is incorrect. Eliminate this option.

'The energy an object has due to its motion' is the correct definition of kinetic energy. This is the only option that remains.

The formula for kinetic energy is $E_k=\frac{1}{2}m{v}^2$ We have $m=0.06$ kg and $v=20$ m/s.

Always square the velocity before multiplying: $v^2=20^2=400{\text{ m}}^2/{\text{s}}^2$

$E_k=\frac{1}{2}\times 0.06\times 400=0.5\times 0.06\times 400=12\text{ J}$

The kinetic energy of the tennis ball is 12 J. Always include the unit joules (J) in your answer.

We need $E_k=\frac{1}{2}m{v}^2$ with $m=0.06$ kg and $v=20$ m/s. The key check is whether $v$ was correctly squared.

1.2 J would come from $\frac{1}{2}\times 0.06\times 20=0.6$ or a similar arithmetic slip without squaring. This is too small. Eliminate.

6 J might come from forgetting the $\frac{1}{2}$ factor: $0.06\times 20^2\times \frac{1}{4}=6$, or another incorrect variation. This does not match the correct formula result. Eliminate.

24 J might come from using $\frac{1}{2}\times 0.06\times 20^2\times 2$, doubling the answer incorrectly, or a similar error. Eliminate.

$E_k=\frac{1}{2}\times 0.06\times 400=12\text{ J}$. This is the only answer consistent with the correct formula and values.