Question

A body is initially at rest. It undergoes one-dimensional motion with constant acceleration. The power delivered to it at time t is proportional to

• A. $t^{1/2}$
• B. $t$
• C. $t^{3/2}$
• D. $t^2$

Answer 1

The correct option is B $t$

Given,

$u=0m/s$

$a=$ constant acceleration.

Power delivered, $P=Fv$. . . . .(1)

From 1st equation of motion,

$v=u+at$

$v=0+at=at$

Force, $F=ma$

From equation (1), we get

$P=ma.at$

$P=m{a}^{2}t$

$P\propto t$

Power delivered is dircetly proportional to the time $t$.

The correct option is B.