A body is moving unidirectionally under the influence of a source of constant power supplying energy. Which of the diagrams shown in Fig. 6.5 correctly shows the displacement-time curve for its motion?

According to the question, body is moving unidirectionally

under the influence of a source of constant power supplying

energy. We know that,

power=force× velocity

P=F× v

P=ma× v…… (1)

We also know that, v=u+at…. (2)

V=at (∵ u=0 body starts initially from rest)

From eq (1) and (2)

P=ma× at

P =

… (3)

We also know that,

(∵ u=o)….(4)

From eq (3) and (4)

⇒

From the above equation we see that s is directly proportional to

Displacement-time graph is correctly shown by Option (b).