Question

A boat that can travel at 4.60 km/h in still water crosses a river with a current of 1.80 km/h. At what angle must the boat be pointed upstream to travel straight across the river

Answer 1

Answer:

The angle the boat must be pointed upstream is 69⁰

Explanation:

Check the image uploaded for the diagram;

Given;

speed of the boat on still water, = 4.6 km/h

speed of the boat on a river with current, = 1.8 km/h

The angle the boat must be pointed upstream is calculated as follows

$tan(\theta) = \frac{4.6}{1.8} \\\\tan(\theta) = 2.556\\\\\theta = tan^{-1}(2.556)\\\\\theta = 68.63^0\\\\\theta = 69^0$