Question

A goldfish swims through an aquarium by moving its fins and tail. What causes the fish to move forward?
I. The force exerted by the water on the goldfish.
II. The force exerted by the tail of the goldfish on the water.
III. The force exerted by the fins of the goldfish on the water.
A. I only
B. II only
C. I and III only
D. II and III only
E. I, II, and III only

Answer 1

Hint: The movement in water is done with the help of precision and it is done by the fishes with the help of the fish’s fins, body, tails and body muscles. The body of fish also adds to this as they have a streamlined body that is similar to a boat.

Complete answer:
The movement in water is done with the help of precision and it is done by the fishes with the help of the fish’s fins, body, tails and body muscles. The body of fish also adds to this as they have a streamlined body that is similar to a boat. The locomotion is also enhanced by water jets that are expelled from gills; these are generally seen in large fishes like whales. According to this question, the answer is going to explain with the help of Newton’s law is the third law, in this law newton’s explained that to every action there is an equal and opposite reaction to it. So when the goldfish swims the fins of the fish exert backward force on the water and the same in the tails it also exerts the backward force action on the water and in response to all the backward force the water gives reaction in forwarding direction. Thus, help in swimming the goldfish in the forward direction.

Hence, option E is the correct answer that is I, II, and III only.

Note:
Many types of fins provide locomotion to fishes like dorsal fins that are present on the back and help the fish to balance in jerky movements, pectoral fins there are found on side of the fish body, caudal fins present on the tail side and hence known as tail fins, anal fins are found on the bottom side. Finlets are the very tiny fins found behind the dorsal fins and anal ones.