A car starts from rest and moves with uniform acceleration $'a'$ on a straight road from time $t = 0$ to $t = T$ . After that, a constant deceleration $'a'$ brings it to rest. In this process the average speed of the car is

A body has speed $V, 2\,V$ and $3\,V$ in first $1/3$ of distance $S$, second $1/3$ of $S$ and third $1/3$ of $S$ respectively. Its average speed will be :-

A bus travelling the first one-third distance at a speed of $10\; km/h$, the next one-third at $20\; km/h$ and at last one-third at $60\; km/h$. The average speed of the bus is ........ $km/h$

A $150 \,m$ long train is moving with a uniform velocity of $45 \,km/h$. The time taken by the train to cross a bridge of length $850 $ meters is..........$sec$

If the body covers one-third distance at speed $v_1$, next one third at speed $v_2$ and last one third at speed $v_3$, then average speed will be

A particle moves along a semicircle of radius $10\,m$ in $5$ seconds. The average velocity of the particle is...........$ms^{-1}$