The speed-time graph of a body is a straight line parallel to the time axis. The body has:

$(a)$ 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?

$A$ cyclist driving at $5\, m s^{-1}$ picks up a velocity of $10\, m s^{-1}$ over a distance of $50\, m$. Calculate $(i)$ acceleration $(ii)$ time in which the cyclist picks up the above velocity.

Ravi told his friend that his house is $1 \,km$ toward south from the main Post Office. Express the displacement and the distance moved by the friend from the Post Office when he arrives at Ravi's house. Mention the reference point chosen by you.

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

What do you understand by the term acceleration? When is it positive and when is it negative?