A car starts from Bengaluru, goes 50 km in a straight line towards south, immediately turns around and returns to Bengaluru. The time taken for this round trip is 2 hours. The magnitude of the average velocity of the car for this round trip
is 0.
is 50 km/hr.
is 25 km/hr.
cannot be calculated without knowing acceleration.
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC NDA-2 – 2019
Total displacement = Final position – Initial position = Bengaluru – Bengaluru = 0 km.
Total time taken = 2 hours.
Average velocity = Total displacement / Total time = 0 km / 2 hours = 0 km/hr.
The magnitude of the average velocity is the absolute value of the average velocity, which is $|0| = 0$.
– Displacement is the shortest straight-line distance from the starting point to the ending point, along with direction. If the start and end points are the same, displacement is zero.
– Average speed is a scalar quantity and depends on the total distance traveled divided by the total time. In this case, the average speed is 100 km / 2 hr = 50 km/hr.
– The acceleration is not constant during the trip (it changes direction when turning around), but this information is not needed to calculate average velocity, which only depends on total displacement and total time.