Question

A body at rest can have:
A. speed
B. energy
C. momentum
D. velocity

Answer 1

Hint: First we know here the concept of energy at rest that means there are two forms of energy i.e. potential energy and kinetic energy potential energy is also called latent energy in an object at rest and kinetic energy, is the energy expressed by an object in motion.

Complete step by step answer:
A body at rest then its position does not change if position is not changing then the velocity becomes zero.
$\therefore \dfrac{{{\text{dx}}}}{{{\text{dt}}}} = 0$
Here dx is the displacement, and the $dt$ is a small change in time.
From here we conclude that when velocity becomes zero then the speed is also zero this means the kinetic energy also becomes zero.
Now we know that momentum is the product of mass and velocity.
$\therefore {\text{v = 0 }} \Rightarrow {\text{ mv = 0 }}$but ${\text{m}} \ne 0$
Here $v$ is velocity and m is mass, this shows that momentum also becomes zero.
But the body is at some height due to gravity and if it is at rest. Still, it possesses some potential energy which when released will be converted into kinetic energy. So the body at rest can have energy.

$\therefore$ The correct option is (B).

Note:
Here the term energy is the quantitative property that must be transferred from one object to another by doing some work. It is the conserved quantity, thus the law of conservation states that energy can neither be created nor be destroyed and can easily be converted into from one form to another. Basically it is the combination of two forms of energy i.e. kinetic energy and potential energy.