Answer:
2:5
Explanation:
We have the initial mass of the fish = 4.5kg
The mass of water intake = 40%of 4.5kg
= 0.40x4.5kg
= 1.8kg
The formula for conserving momentum
M1V1 = M2V2
M1 = mass of the puffer fish = 4.5kg
M2 = mass of the applied water = 1.8kg
V1 = velocity of the puffer fish
V2 = velocity of water
We are then to find v1/v2
V1/V2 = M2/M1
V1/V2 = 1.8/4.5
= 1/2.5
This is also 2/5
Therefore we have the ratio to be 2:5