State whether the following statement is true or false:
Motion along a curved line is called translatory or rectilinear motion.

Two stones are thrown vertically upwards simultaneously with their initial velocities $u_{1}$ and $u_{2}$ respectively. Prove that the heights reached by them would be in the ratio of $u_{1}^{2}: u_{2}^{2}$ (Assume upward acceleration is $-g$ and downward acceleration is $+g$).

$(a)$ 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 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?

How can you find the following?
$(i)$ Velocity from a displacement-time graph.
$(ii)$ Acceleration from a velocity-time graph.
$(iii)$ Displacement from a velocity-time graph.
$(iv)$ Velocity from an acceleration-time graph.

$A$ person standing at $A$ goes to $B$ by following any of the paths $1, 2$ or $3$. Which path can we measure to find the average velocity?