A car starts from rest and moves along the $x-$ axis with constant acceleration $5\, ms^{-2}$ for $8\,\sec $. If it then continues with constant velocity, what distance will the car cover in $12\,\sec $ since it started from the rest ?

A train $100 \,m$ long is moving with a velocity of $60\, km h^{-1}$. Find the time it takes to cross the bridge $1\, km$ long.

Define 'average speed'. An object moves with a uniform speed of $10\, m s ^{-1}$ for $5 s$ and then with a uniform speed of $5\, m s ^{-1}$ for $10\, s$. Find its average speed.

The distance$-$time graph of a body is a straight line inclined to time axis. The body is in

Explain the differences between the two graphs.