Question

A body at rest starts moving under the action of a constant force along a straight line. The instantaneous power developed by this force with time $\text{t}$ is correctly represented by

• A.
• B.
• C.
• D.

Answer 1

The correct option is B

We know that acceleration, $a=\frac{F}{m}$
By the equation of motion, $v=u+at=\frac{F}{m}t$ ( $u=0$ , because body statrs from rest )

$P=F.v=\left(\frac{F^2}{m}\right)t$
or $P\propto t$
i.e. $P-t$ graph is a straight line passing through origin.

Hence option B is the correct answer