Final answer:
The 5-kilogram fish has more momentum than the 2-kilogram fish.
Step-by-step explanation:
The momentum of an object is given by the formula: momentum = mass * velocity. Therefore, we can calculate the momentum of each fish using this formula. For the 5-kilogram fish swimming at a speed of 10 meters/second, the momentum will be: 5 kg * 10 m/s = 50 kg m/s. For the 2-kilogram fish swimming at the same speed, the momentum will be: 2 kg * 10 m/s = 20 kg m/s.
Therefore, the 5-kilogram fish has more momentum than the 2-kilogram fish. So, the statement that best compares the momentum of the two fish is: The 5-kilogram fish has more momentum.