Under what condition(s) is the magnitude of average velocity of an object? Class 9

Under what condition(s) is the magnitude of average velocity of an object? Class 9

Question 1.

Under what condition(s) is the

(i) magnitude of average velocity of an object equal to its average speed?

(ii) magnitude of average velocity of an object zero while its average speed is not zero? Class 9

Answer:

(i) The magnitude of average velocity is equal to average speed when: The object moves in one direction only, without turning back, i.e., when the object moves in a straight line in one direction throughout the entire time interval. In this case, the total distance travelled = the magnitude of displacement, so average speed = magnitude of average velocity.

For example, a car moving from point A to point B along a straight road without reversing - both average speed and magnitude of average velocity are the same.

(ii) The magnitude of average velocity is zero while average speed is not zero when: The object starts and ends at the same position (returns to the starting point) but has actually travelled some distance. In this case, displacement = 0, so average velocity = 0. But since the object has covered some distance, average speed is not zero. Examples: An athlete running one complete lap on a circular track and returning to the starting line.