Ali while driving to school computes the average speed for his trip to be $20\, km h^{-1}$. On his return trip along the same route there is less traffic and the average speed is $30\, km h^{-1} .$ What is the average speed for Ali's trip ?

Distinguish between terms speed and velocity.

A frog hops along a straight line path from point $'A^{\prime}$ to point ${ }^{\prime} B ^{\prime}$ in $10\, s$ and then turns and hops to point ${ }^{\prime} C^{\prime}$ in another $5\, s$. Calculate the average speed and average velocity of the frog for the motion between $(a)(A)$ to $(B)(b)(A)$ to $(C)($ through $B)$

The position$-$time graph for the motion of a car is given below

$(i)$ How far the car tavelled in the time interval $2$ to $6 s ?$

$(ii)$ During which interval of time its speed was more?

$(iii)$ Calculate the average speed of the car.

A body is thrown vertically upward with velocity $u$, the greatest height $h$ to which it will rise is,