Answer: 721.1 km/h, at 86.6 degrees north of west
Explanation:
The magnitude of the velocity of the plane can be found by calculating the resultant of the two velocities:
[tex]R=\sqrt{(720 km/h)^2+(40 km/h)^2}=721.1 km/h[/tex]
The direction can be found as follows:
[tex]\theta = tan^{-1} (\frac{720 km/h}{40 km/h})=86.8^{\circ}[/tex]
where 720 km/h represents the velocity towards north, while 40 km/h represents the velocity towards west, so the angle is measured with respect to east. Therefore:
the direction is [tex]86.8^{\circ}[/tex] north of west
