KinematicsHard
Question
Pick the correct statement : -
Options
A.Average speed of a particle in a given time is never less than the magnitude of the average velocity
B.It is possible to have a situation in which 
≠ 0 but 
= 0.
≠ 0 but = 0.C.The average velocity of a particle is zero in a time interval. It is possible that the instantaneous velocity is never zero in the interval.
D.The average velocity a particle moving on a straight line in a time interval. It is possible that the instantaneous velocity is never zero in the interval. (in fine acceleration is not allowed)
Solution
[A] ∵ Distance > Displacement
∴ Average speed > Average velocity
[B] |
| ± 0 ⇒ ᐃ 
± 0
Velocity can change by changing its direction
[C] Ava rage velocity by changing its direction Average velocity depends on displacement in time interval e.g. circular motion → after one revolution displacement become zero hence average velocity but instantaneous velocity never becomes zero during motion.
[D] In a straight line motion ; there must be reversal of the direction of velocity to reach the destination point for making displacement zero and hence instantaneous velocity has to be zero at least once in a time interval.
∴ Average speed > Average velocity
[B] |
| ± 0 ⇒ ᐃ ± 0Velocity can change by changing its direction
[C] Ava rage velocity by changing its direction Average velocity depends on displacement in time interval e.g. circular motion → after one revolution displacement become zero hence average velocity but instantaneous velocity never becomes zero during motion.
[D] In a straight line motion ; there must be reversal of the direction of velocity to reach the destination point for making displacement zero and hence instantaneous velocity has to be zero at least once in a time interval.
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