JEE Main Physics question
Two solid rubber balls A and B having masses 200 and 400 g respectively are moving in opposite directions with velocity of A equal to 0.3 m/s. After collision the two balls come to rest, then the velocity of B is [CPMT 1978, CPMT 1986, CPMT 1988]
Answer: (C)
Solution
By conservation of momentum (taking A's direction as positive): 0.2(0.3) + 0. = 0 ⟹ = −0.06/0.4 = −0.15 m/s.