Question

A 3 kg fish is swimming at 1.5 m/s to the right. It swallows a 0.25kg

fish swimming to the left at 4.0 m/s. What is the velocity of the larger
immediately after lunch?
Show Your Work

Answer 1

1.076 m/s

Step-by-step explanation:

Given a 3.0 kg fish is swimming at 1.5 m/s to the right. it swallows a 0.25 kg fish swimming to the left at 4.0 m/s. what is the speed and direction of the larger fish immediately after lunch?

Mass of fish m1 = 3 kg

Velocity v1 = 1.5 m/s

Mass of small fish m2 = 0.25 kg

Velocity v2 = - 4 m/s (negative sign since the direction is opposite)

Therefore total mass of fish after swallowing will be M = 3 + 0.25 = 3.25 kg

Let the final velocity of fish be V

Now according to the law of conservation of momentum we have

So m1v1 + m2v2 = M x V

3 x 1.5 + 0.25 x – 4 = 3.25 x V

4.5 – 1 = 3.25 V

3.25 V = 3.5

Or V = 1.076 m/s

So speed of the fish will be 1.076 m/s