A train is travelling at a speed of $90\, km h ^{-1}$. Breaks are applied so as to produce a uniform acceleration of $0.5\, m s ^{-2}$. Find how far the train will go before it is brought to rest.

An object starting from rest travels $20\, m$ in first $2\,\sec $ and $160\, m$ in next $4\,\sec $. What will be the velocity after $7\,\sec $ from the start ?

$(a)$ Write differences between speed and velocity.

$(b)$ The speed of a moving object is $x m s ^{-1}$. Its velocity is $y m s ^{-1}$. What is the similarity observed ?

The direction of acceleration of an object moving in a circular path is

The velocity-time graph of cars $A$ and $B$ which start from the same place and move along a straight road in the same direction is shown below

Calculate :

$(a)$ the acceleration of car $B$ between $2 \,s$ and $4\, s$.

$(b)$ the time at which both the cars have the same velocity.

$(c)$ the distance travelled by the two cars $A$ and $B$ in $8\, s$

$(d)$ Which of the two cars is ahead after $8\, s$ and by how much ?