Question

Ronjeev is paddling a kayak across a river. He wants to paddle the kayak straight across the river from east to west at a velocity of 12 kilometers per hour. However, there is a current flowing south that is pushing his kayak downstream at a velocity of 5 kilometers per hour. What is the actual velocity, in kilometers per hour, of the kayak? A 7 B 12 C 13 D 17

Answer 1

Option C is the correct answer.

Explanation:

Refer the figure.

We need to find resultant of two perpendicular vectors, that is the actual velocity.

Velocity of Ronjeev = 12 kilometers per hour

Velocity of River = 5 kilometers per hour

`\texttt{Actual velocity = }\sqrt{\texttt{Velocity of Ronjeev}^2+\texttt{Velocity of River}^2}\\\\\texttt{Actual velocity = }√(12^2+5^2)=√(144+25)=√(169)\\\\\texttt{Actual velocity = }13kmph`

Option C is the correct answer.