Work Energy And Power Question 263
Question: A constant power P is applied to a car starting from rest. If v is the velocity of the car at time t, then
Options:
A) $ v\propto t $
B) $ v\propto \frac{1}{t} $
C) $ v\propto \sqrt{t} $
D) $ v\propto \frac{1}{\sqrt{t}} $
Show Answer
Answer:
Correct Answer: A
Solution:
[a] Power, $ P=F.v=m\frac{dv}{dt}.v $
As P is constant, $ \frac{v}{dt}= $ constant
$ \Rightarrow v\propto dt\Rightarrow v\propto t $
