Applications Of Derivatives Question 327
Question: The equation of motion of a particle moving along a straight line is $ s=2 $ $ t^{3}-9t^{2}+12t $ , where the units of s and t are cm and sec. The acceleration of the particle will be zero after
Options:
A) $ \frac{3}{2},sec $
B) $ \frac{2}{3}sec $
C) $ \frac{1}{2}sec $
D) Never
Show Answer
Answer:
Correct Answer: A
Solution:
$ \frac{ds}{dt}=6t^{2}-18t+12 $
Again $ \frac{d^{2}s}{dt^{2}}=12t-18 $ = acceleration
If acceleration becomes zero, then $ 0=12t-18 $
therefore $ t=\frac{3}{2}\sec . $
Hence acceleration will be zero after $ \frac{3}{2} $ sec.
BETA
