A body moving with uniform acceleration has velocities $20 \,m s ^{-1}$ and $30\, m s ^{-1}$. when passing two points $A$ and $B$. Then the velocity midway between $A$ and $B$ is

List two differences in tabular form between speed and velocity. When is a body said to have :
$(a)$ uniform velocity and $(b)$ variable velocity. How is the average velocity of a body is calculated when its velocity changes at a non$-$uniform rate ?

The velocity$-$time graph of a truck is plotted below

$(a)$ Calculate the magnitude of displacement of the truck in $15$ seconds.

$(b)$ During which part of the journey was the truck decelerating ?

$(c)$ Calculate the magnitude of average velocity of the truck.

An electron moving with a velocity of $5 \times 10^{4}\, ms ^{-1}$ enters into a uniform electric field and acquires a uniform acceleration of $10^{4}\, ms ^{-2}$ in the direction of its initial motion.

$(i)$ Calculate the time in which the electron would acquire a velocity double of its initial velocity.

$(ii)$ How much distance the electron would cover in this time ?

A person travelling in a bus noted the timings and the corresponding distances as indicated on the km stones. (a) Name this type of table $(b)$ What conclusion do you draw from this data ?