Identical balls A and B move with velocities +0.5 m s⁻¹ and -0.3 m s⁻¹ respectively and undergo a head-on elastic collision. Find the velocities of B and A after collision, respectively.
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Identical balls A and B move with velocities +0.5 m s⁻¹ and -0.3 m s⁻¹ respectively and undergo a head-on elastic collision. Find the velocities of B and A after collision, respectively.

G1 Physics · Accepted Answer

Step 1 — Principle: For a one-dimensional elastic collision, conserve momentum and kinetic energy. Step 2 — Working: Identical masses exchange velocities in a 1D perfectly elastic collision. Step 3 — Working: Thus B gets A's +0.5 m/s and A gets B's -0.3 m/s; the requested order is (+0.5,-0.3). Correct answer: B — 0.5 m/s and -0.3 m/s.