Work Energy And Power Question 151
Question: A particle of mass 0.1 kg is subjected to a force which varies with distance as shown in the figure. If it starts its journey from rest at $ x=0 $ , its velocity at $ x=12 $ m is
Options:
A) $ 0m/s $
B) $ 20\sqrt{2}m/s $
C) $ 20\sqrt{3}m/s $
D) $ 40m/s $
Show Answer
Answer:
Correct Answer: D
Solution:
[d] Area between curve and displacement axis $ =\frac{1}{2}\times (12+4)\times 10=80J $
In this time, body acquires kinetic energy = $ \frac{1}{2}mv^{2} $
By the law of conservation of energy $ \frac{1}{2}mv^{2}=80J $
$ \Rightarrow \frac{1}{2}\times 0.1\times v^{2}=80 $
$ \Rightarrow v^{2}=1600 $
$ \Rightarrow v=40m/s $
