Question

A car travels 15 kilometers west in 10minutes. After reaching the destination , the car travels back to the starting point ,again taking 5minutes .what is the average velocity of the car

Answer 1

Before I reveal the car's average velocity,

let me calculate the car's average SPEED:

Average speed = (total distance covered) / (time to cover the distance)

Total distance covered = (15km + 15km) = 30 km

Time to cover the distance = (10min + 5min) = 15 minutes = 1/4 hour

Average speed = (30km) / (1/4 hour)

Average speed = 120 km per hour

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Average velocity = (displacement) / (time in motion)

Displacement = (straight-line distance and direction from start to finish)

Time in motion = (time between starting and finishing)

This car finished at the same point it started from,

so its displacement was zero.

Time in motion = (10min + 5min) = 15 minutes = 1/4 hour

Average velocity = (Zero) / (1/4 hour)

Average velocity = Zero .