A car is moving along a straight (OP). It moves from `O to P` in `18 seconds` amd retuns from `P to Q` in 6 seconds`, where `OP=360 m` and `OQ=240 m What are the car the average velcoty and average speed of the car in going (a) from `Oto P` and back to `Q` ?

Explanation

Average velocity `= ("Displacement")/("Time interval")`
`bar(v) = (+360 m)/(18s) = + 20 m s^(-1)`
Average speed `= ("Path length")/("Time interval")`
`= (360m)/(18s) = 20 ms^(-1)`
Thus, in this case the average is equal to the magnitude of the average velocity.
(b) In this case,
Average velocity `= ("Displacement")/("Time interval") = (+240 m)/((18 + 6.0)s)`
`= + 10 ms^(-1)`
Average speed `= ("Path length")/("Time interval") = (PO + PQ)/(Delta t)`
`= ((360 + 120)m)/(24 s) = 20 ms^(-1)`