Question

iclicker which one of the following statements concerning kinetic energy is true? a. kinetic energy is always positive. b. kinetic energy is always equal to the potential energy. c. kinetic energy is directly proportional to velocity. d. kinetic energy is a quantitative measure of inertia. e. kinetic energy can be measured in watts.

Explanation:

• Kinetic energy is given by $K = \frac{1}{2}mv^{2}$, where mass $m>0$ and $v^{2}\geq0$. Since mass is non - negative and squared velocity is non - negative, kinetic energy is always non - negative and positive for non - zero velocity. It is not always equal to potential energy. It is proportional to the square of velocity, not velocity directly. Inertia is measured by mass, not kinetic energy. The unit of kinetic energy is joules, not watts.

Answer:

A. Kinetic energy is always positive.