Applications Of Derivatives Question 53

Question: If the distance -s- traveled by a particle in time t is $ s=a\sin t+b\cos 2t $ , then the acceleration at t = 0 is

Options:

A) a

B) - a

C) 4b

D) - 4b

Show Answer

Answer:

Correct Answer: D

Solution:

Given $ s=a\sin t+b\cos 2t $

$ \therefore $ $ \frac{ds}{dt}=a\cos t-2b\sin 2t $

$ \frac{d^{2}s}{dt^{2}}=-a\sin t-4b\cos 2t $ At $ t=0 $ , $ \frac{d^{2}s}{dt^{2}}=-a\sin 0{}^\circ -4b\cos 0{}^\circ =-4b $ .