How is the velocity obtained from the displacement-time graph for a body moving with a varying speed in a fixed direction?

What can you say about the nature of motion of a body if its displacement-time graph is —

(a) a straight line parallel to time axis?

(b) a straight line inclined to the time axis with an acute angle?

(c) a straight line inclined to the time axis with an obtuse angle?

(d) a curve

Draw a velocity-time graph for a body moving with an initial velocity u and uniform acceleration a. Use this graph to find the distance travelled by the body in time t.

State how the velocity-time graph can be used to find —

(i) the acceleration of a body,

(ii) the distance travelled by the body in a given time, and

(iii) the displacement of the body in a given time.