Identify what do the graphs shown below indicate ?

Name the physical quantities denoted by

$(i)$ The slope of the distance$-$time graph.

$(ii)$ The area under velocity$-$time graph.

$(iii)$ The slope of velocity$-$time graph.

A piece of stone is thrown vertically upwards. It reaches its maximum height in $3$ second. If the acceleration of the stone be $9.8\, m s ^{-2}$ directed towards the ground, calculate the initial velocity of the stone with which it is thrown upwards. Find the maximum height attained by it.

Following figure is the speed-time graph for a rocket from the moment when the fuel starts to burn, i.e. at time $t=0$.

$(a)$ State the acceleration of the rocket at $t=0$.

$(b)$ State what happens to the acceleration of the rocket between $t=5 s$ and $t=60 s$.

$(c)$ Calculate the acceleration of rocket at $t=80 s$ Give reason for your answer.

$(d)$ The total mass of the rocket at $t=80\, s$ is $1.6 \times 10^{6}\, kg .$ Calculate the resultant force on the rocket at this time. Give reason for your answer.

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 ?