What is the slope of the displacement $-$ time graph when the body has uniform motion?

Prove that if a body is thrown vertically upward,the time of ascent is equal to the time of descent.

State whether the following statement is true or false:
$A$ quantity which can be completely specified by magnitude as well as direction is called a scalar quantity.

"The direction in which an object moves is given by the direction of velocity of the object and not by the direction of acceleration." Give an example to justify this statement.

Study the speed-time graph of a body given below and answer the following questions:
$(i)$ What type of motion is represented by $OA$,$AB$ and $BC$?
(ii) Find positive and negative accelerations of the body.
(iii) Find the distance travelled by the body from $A$ to $B$.

Can the distance travelled by a particle be zero when displacement is not zero?