Question

A car is pushed by some force from rest. Power delivered to car varies linearly with time as shown, then graph of K.E. with respect to time would be

• A.
• B.
• C.
• D.

Answer 1

The correct option is B

$P=\frac{dW}{dt}=\frac{d(K.E.)}{dt}=c.t$
$d(K.E.)=c.tdt$
$K.E.=\frac{c{t}^2}{2}$ + constant
Which means graph between $K.E.$ and $t$ will be a parabola having its line of symmetry parallel to $K.E.$.Since car starts moving from rest, hence option(b) is the right answer.