Answer:
1.33m/s
Explanation:
Given parameters:
M1 = 20kg
V1 = 2m/s
V2 = 0m/s
M2 = 10kg
Unknown:
V = ?
Solution:
As with all systems, the momentum must be conserved and it implies that the starting and ending momentum be the same.
M1 V1 + M2 V2 = V (M1 + M2)
M1 is the mass of the big red fish
V1 is the velocity of the big red fish
V2 is the velocity of the green fish
M2 is the mass of the green fish
V is the velocity after swallowing
(20 x 2) + (10 x 0) = V (20 + 10)
40 = 30V
V = 1.33m/s