OnlineCBT
Physics · WORK, ENERGY AND POWER
हिन्दीConsider the following statements regarding a one-dimensional collision between two particles of masses \( m_1 \) and \( m_2 \): (A) Linear momentum of the two-particle system is conserved in both elastic and inelastic collisions. (B) Kinetic energy of the system is conserved before and after an elastic collision. (C) In a completely inelastic collision, the kinetic energy of the system after collision is always zero in every reference frame. (D) For an elastic collision, the relative velocity of separation equals the relative velocity of approach. Choose the correct answer from the options given below:
Correct answer · Option 3
(A), (B) and (D) only
Explanation
Statements (A), (B), and (D) are true for elastic collisions (\( v_{2f} - v_{1f} = v_{1i} - v_{2i} \)). Statement (C) is false because in the lab frame, the combined body moves with speed \( v_f = \frac{m_1 v_{1i}}{m_1 + m_2} \neq 0 \), so its kinetic energy is non-zero.
