Question

A body at rest can have
A. Speed
B. Energy
C. Momentum
D. Relative velocity

Answer 1

A body at rest means the state of an object which doesn't change its position with the change of time. that means the object has no speed as speed means the covered distance by an object within a certain time. Since there is no existence of absolute rest or absolute motion. The state of an object is observed from a particular frame of reference. So we can say the body has a relative velocity concerning any other object or frame of reference.

Complete step by step answer:
A body at rest means the state of an object which doesn't change its position with the change of time. That means the object has no speed as speed means the covered distance by an object within a certain time.
Now, we consider the given options:
Speed- a body at rest means it does not change its position with the change of time. So it must have no speed.
Energy- when an object is kept at some height above the surface, it gains energy that we call as gravitational potential energy. We can also say, when an object is taken against an external force acting on it, from some other source it will gain potential energy (not only due to gravity). Therefore, a body at rest stores energy here, which is called potential energy.
Momentum- The momentum of any object that is at rest is zero. Objects at rest do not have momentum as they do not have any "mass in motion". Both variables - mass and velocity - are important for calculating momentum. Momentum= Mass × Velocity.
Relative velocity - there is no existence of absolute rest or absolute motion. The state of an object is observed from a particular frame of reference. So we can say the body has a relative velocity concerning any other object or frame of reference.
Hence, the correct answers are in option (B) and option (D).

Note:
Equation of speed, $v = \dfrac{{s(dis\tan ce)}}{{t(time)}}$
Equation of Energy, Kinetic Energy, $K.E = \dfrac{1}{2}m(mass) \times {v^2}(velocity)$
And, Potential energy, $P.E = m(mass) \times g(gravitational.ac.) \times h(height)$
Equation of Momentum, $P = m(mass) \times v(velocity)$