Question

A car goes from A to B, 100 km, in two hours and returns back from B to A in 3 hrs. Calculate : [2]
(i) its average speed
(ii) its average velocity

Answer 1

Average speed = 40 km/hr; average velocity = 0

Explanation:

Distance from A to B = 100 km

Time = 2 hours.

Speed = Distance / time = 100/2 = 50 km/hr

Return distance = 100 km

Return Time = 3 hrs

Return Speed = 100 / 3 km/hr

Average speed = Total distance / total time = 200 / 5 = 40 km/hr

(ii) As the car returns to the start point, the displacement is zero.

Average velocity = displacement/time = 0