The kinetic energy of an object is quadrupled.Its momentum will change by what factor?
A)zero
B)two
C)eight
D)four

Question

Quizplus · Accepted Answer

The kinetic energy (K) of an object is given by $K = \frac{1}{2}mv^2$, where $m$ is the mass and $v$ is the velocity. Momentum (p) is given by $p = mv$. If the kinetic energy is quadrupled, then the new kinetic energy is $4K = \frac{1}{2}mv'^2$, where $v'$ is the new velocity. Solving for $v'$ in terms of $v$, we find that $v' = 2v$. Since momentum is directly proportional to velocity, if the velocity doubles, the momentum also doubles.

The Kinetic Energy of an Object Is Quadrupled