A person walks on a raft moving along the river, the length of the raft is 4 meters and its width is 3 meters.

A person walks on a raft moving along the river, the length of the raft is 4 meters and its width is 3 meters. During the movement of a person from one end of the raft to the other, the raft moves 4 meters relative to the shore. What is the displacement of a person relative to the coast during his movement?

Given:

L1 = 4 meters – movement of the raft relative to the coast;

L2 = 3 meters – movement of a person on the raft.

It is required to determine L3 (meters) – the movement of a person relative to the shore.

According to the condition of the problem, the raft moves along the course of the river, and the person goes from one end of the raft to the other perpendicular to the course of the river and the bank. It turns out that simultaneously with the movement of a person along the raft, the raft also moves, that is, the trajectory of a person’s movement will be the hypotenuse of a right-angled triangle, with legs L1 and L2. Then:

L3 = (L1 ^ 2 + L2 ^ 2) ^ 0.5 = (4 ^ 2 + 3 ^ 2) ^ 0.5 = (16 + 9) ^ 0.5 = 25 ^ 0.5 = 5 meters.

Answer: the movement of a person relative to the shore will be equal to 5 meters.