A ‘m’ kg fish swimming at 2 m/s catches a ‘m/9’ kg fish coming towards it from opposite direction swimming at 3 m/s. The velocity of the larger fish immediately after the grab is:
(A) 1.5ˆi m/s
(B) 2.1ˆi m/s
(C) −1.5ˆi m/s
(D) −2.1ˆi m/s
Solution
This can be considered as inelastic collision. Using conservation of linear momentum along x-direction,
2m−3m9=(m+m9)v
⇒2–13=109v
⇒v=1.5m/s
Hence, (A)