What is the SI unit for kinetic energy?Group of answer choicesNewtonsWattsKelvinsJoules

Identification of the Correct Answer

1. Understanding Kinetic Energy: Kinetic energy is the energy that an object possesses due to its motion. The formula to calculate kinetic energy (KE) is given by:

   $KE = \frac{1}{2}mv^2$

   where $m$ is the mass of the object (in kilograms) and $v$ is the velocity (in meters per second).

2. Determining the SI Unit: The units of each component in the kinetic energy formula are:

   • Mass (m) is measured in kilograms (kg).
   • Velocity (v) is measured in meters per second (m/s).

   Thus, when calculating kinetic energy, the unit derived from the formula is:

   $\text{kg} \cdot \left(\frac{\text{m}}{\text{s}}\right)^2 = \text{kg} \cdot \frac{\text{m}^2}{\text{s}^2}$

   This combination of units is defined as Joules (J) in the SI system.

3. Reviewing the Options: Given the options provided:

   • Newtons (N) are used for force.
   • Watts (W) are used for power.
   • Kelvins (K) are used for temperature.
   • Joules (J) are used for energy.

Final Answer

The SI unit for kinetic energy is Joules (J).