Applications Of Derivatives Question 335
Question: A particle is moving in a straight line according as $ s=45,t+11t^{2}-t^{3} $ then the time when it will come to rest, is
Options:
A) - 9 seconds
B) $ \frac{5}{3} $ seconds
C) 9 seconds
D) $ -\frac{5}{3} $ seconds
Show Answer
Answer:
Correct Answer: C
Solution:
$ \frac{ds}{dt}= $ velocity $ =45+22t-3t^{2} $
When particle will come to rest, then $ v=0 $
therefore $ 3t^{2}-22t-45=0\Rightarrow t=9,( sincet\ne -\frac{5}{3} ) $ .
BETA
