A 5-kg shark swimming at a speed of 1 m/s swallows an absent-minded 1-kg fish swimming toward it at 4 m/s.The speed of the shark after this meal is

Question

Quizplus · Accepted Answer

Before the meal, the total momentum of the system is:
P = (5 kg) x (1 m/s) + (1 kg) x (-4 m/s) = 1 kg m/s to the left.
After the shark swallows the fish, the total mass of the system is 6 kg and the shark's velocity is V. Applying the law of conservation of momentum, we have:
P = (6 kg) x V
Therefore, V = P/6 = (1 kg m/s)/6 kg = 1/6 m/s to the left. Thus, the correct answer is (C).

A 5-Kg Shark Swimming at a Speed of 1 M/s