During a family road trip, you drive 200 km north in three hours. Afterwards, you drive 200 km south in two hours. Find the average speed and average velocity for your entire trip.                                    [Pg. No. 53]

Total distance travelled = $200 + 200 = 400$ km

$$\text{Average speed} = \frac{\text{Total distance}}{\text{Total time}} = \frac{400}{5} = 80 \text{ km/h}$$

Since the final position is the same as the starting position, total displacement = 0.

$$\text{Average velocity} = \frac{\text{Total displacement}}{\text{Total time}} = \frac{0}{5} = 0 \text{ km/h}$$

Hence, since the family returns to the starting point, the net displacement is zero. Therefore, the average speed is 80 km/h and the average velocity is 0 km/h.