Question

The lowest possible mass of a particle is its _____________

(a) Relativistic mass

(b) Inertial mass

(c) Gravitational mass

(d) Rest mass

I have been asked this question in an online interview.

This intriguing question originated from Mass Variation with Velocity in chapter Ultrasonics & Relativity of Engineering Physics I

Answer 1

The correct option is (d) Rest mass

The explanation is: We know the relation, m = \(\frac{m_0}{\sqrt{1-\frac{v^2}{c^2}}}\)

Thus, the minimum velocity one can acquire is zero. For that, the expression reduces to m = m0.

Thus, rest mass is the lowest possible mass of a particle.