A car moves for half of its time at $80\, km/h$ and for rest half of time at $40\, km/h$. Total distance covered is $60 \,km$. What is the average speed of the car.........$km/h$

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..........$sec$

A car is moving along a straight line, say $OP$ in given figure. It moves from $O$ to $P$ in $18\; s$ and returns from $P$ to $\mathrm{Q}$ in $6.0\; s$. What are the average velocity and average speed of the car in going from $O$ to $P$?

A body covers first one-third of the distance with a velocity $20\, ms^{-1}$, the second one-third with a velocity of $30\, ms^{-1}$ and last one-third with a velocity of $40\, ms^{-1}$. The average velocity is nearly........$m/s$

A particle covers half of its total distance with speed $v_1$ and the rest half distance with speed $v_2 .$ Its average speed during the complete journey is 

A car travels a distance of $x$ with speed $v_1$ and then same distance $x$ with speed $v_2$ in the same direction. The average speed of the car is