A rocket accelerates at 2 m s⁻² along +x in gravity-free space. Inside it is a 4 m long chamber. A ball is thrown from the left end at 0.3 m s⁻¹ along +x relative to the rocket, while another is thrown simultaneously from the right end at 0.2 m s⁻¹ along -x relative to the rocket. Find the time in seconds when the two balls hit each other.

Question

G1 Physics · Accepted Answer

In the accelerating rocket frame both balls experience the same pseudo-acceleration toward -x, and the chamber boundaries constrain their subsequent motion. Following the wall interactions intended by the source setup gives the collision time 2 s. The printed JEE Advanced answer key is [2].