A meteorologist tracks the movement of a thunderstorm with Doppler radar. At 8:00pm the storm was 55 mi northeast of her station. At 11:00 pm the storm is at 75 mi north. What's the direction of the average velocity of the storm? And the magnitude of the average velocity of the storm?

At 8:00 pm, the velocity of the storm is 55 mi northeast. Assuming that the direction is exactly northeast, the angle is 45°

At 11:00 pm, the velocity is 75 mi north. The angle is 90°

In vector form

55 ∠ 45°

and

75 ∠ 90°

The magnitude and direction of the average velocity is

(55 ∠ 45° + 75 ∠ 90°) / 3