Question

A ferry is traveling at 15 m/s relative to the riverbank in the direction the river is flowing. The river is flowing at 2 m/s relative to the riverbank. What is the ferry's velocity relative to the river?

a) 13 m/s
b) 15 m/s
c) 17 m/s
d) 20 m/s

Answer 1

The ferry's velocity relative to the river is calculated by subtracting the river's velocity from the ferry's velocity relative to the riverbank, resulting in 13 m/s.

Step-by-step explanation:

The question refers to calculating the ferry's velocity relative to the river. We know that the ferry travels at 15 m/s relative to the riverbank and that the river is flowing in the same direction at 2 m/s relative to the riverbank. To find the ferry's velocity relative to the river, we subtract the river's velocity from the ferry's velocity relative to the riverbank. This way, we account for the movement of the river itself. Hence:

• Ferry's velocity relative to the riverbank = 15 m/s
• River's velocity relative to the riverbank = 2 m/s
• Ferry's velocity relative to the river = Ferry's velocity relative to the riverbank - River's velocity relative to the riverbank
• Ferry's velocity relative to the river = 15 m/s - 2 m/s = 13 m/s

Therefore, the correct answer is (a) 13 m/s.