Work Energy And Power Question 222
Question: At time $ t=0s $ particle starts moving along the x-axis. If its kinetic energy increases uniformly with time f, the net force acting on it must be proportional to
Options:
A) $ \sqrt{t} $
B) constant
C) $ t $
D) $ \frac{1}{\sqrt{t}} $
Show Answer
Answer:
Correct Answer: D
Solution:
[d] Given, $ \frac{dk}{dt}= constant $
$ \Rightarrow k\propto t\Rightarrow v\propto \sqrt{t} $
$ Also, P=Fv=\frac{dk}{dt}= constant $
$ \Rightarrow F\propto \frac{1}{v}\Rightarrow F\propto \frac{1}{\sqrt{t}} $
