An airplane is flying north at 500 km/h.It makes a gradual 180° turn at constant speed, changing its direction of travel from north through east to south.The process takes 40 s.The average acceleration of the plane for this turn is:
A)12.5 km/h°s, north
B)12.5 km/h°s, east
C)12.5 km/h°s, south
D)25 km/h°s, north
E)25 km/h°s, south

Question

Quizplus · Accepted Answer

The average acceleration can be calculated using the change in velocity over time. The plane changes its velocity direction from north to south, maintaining the same speed. The magnitude of the velocity change is twice the speed (500 km/h north to 500 km/h south), which is 1000 km/h. Over 40 seconds, the average acceleration is $ \frac{1000 \, \text{km/h}}{40 \, \text{s}} = 25 \, \text{km/h} \cdot \text{s}^{-1} $, directed south because the change in velocity is towards the south.

An Airplane Is Flying North at 500 Km/h