A migrating bird will travel nonstop at a fixed speed of 40 km/hr (in still air) over a distance of 2000 km due south of its present position; however, there is a west wind of 30 km/hr. What is the time required for the bird to reach its destination?
A)37.8 hours
B)53.5 hours
C)75.6 hours
D)106.9 hours

Question

Quizplus · Accepted Answer

The bird's southward speed is the resultant of its velocity and the wind's effect. Using the Pythagorean theorem, the southward speed is √(40^2 - 30^2) = 30 km/hr. Time = distance/speed = 2000 km / 30 km/hr = 66.67 hours. However, the correct calculation should consider the full vector addition, resulting in a time of 75.6 hours.

A Migrating Bird Will Travel Nonstop at a Fixed Speed