Applications Of Derivatives Question 379
Question: A particle is moving in a straight line. Its displacement at time t is given by $ s=-4t^{2}+2t $ , then its velocity and acceleration at time $ t=\frac{1}{2} $ second are
[AISSE 1981]
Options:
A) - 2, - 8
B) 2, 6
C) - 2, 8
D) 2, 8
Show Answer
Answer:
Correct Answer: A
Solution:
Displacements $ s=-4t^{2}+2t $
Now velocity $ v=-8t+2 $ and its acceleration $ a=-8 $
So $ {{( \frac{ds}{dt} )} _{t=1/2}}=-8\times \frac{1}{2}+2=-2 $ and $ {{( \frac{d^{2}s}{dt^{2}} )} _{t=1/2}}=-8 $ .
BETA
