Which of the following is not a vector?

The distance-time graph of a body is a straight line inclined to the time axis. The body is in:

Define acceleration. State a relationship connecting $u, v, a$ and $t$ for an accelerated motion. Give an example of a motion in which acceleration is uniform.

$A$ train $100 \, m$ long is moving with a velocity of $60 \, km/h$. Find the time it takes to cross a bridge $1 \, km$ long.

$(a)$ When will you say a body is in $(i)$ uniform motion $(ii)$ non-uniform motion?
$(b)$ Show the path of an object when it is in uniform motion with the help of a graph.

What is meant by free fall? Two bodies,one of mass $1\,g$ and other of mass $1\,kg$,are dropped from the same height in a vacuum. Compare the two time intervals in which the two bodies will hit the ground.