NEET Solved Paper 2014 Question 8
Question: The oscillation of a body on a smooth horizontal surface is represented by the equation, $ X=A\cos (\omega t) $ where X = displacement at time t, $ \omega $ = frequency of oscillation. Which one of the following graphs shows correctly the variation a with t? Note:- Here, a = acceleration at time t, T = time period [AIPMT 2014]
Options:
A) 
B) 
C) 
D) 
Show Answer
Answer:
Correct Answer: A
Solution:
We can find the correct graph by putting different values of t in the given expression
$ x=A\cos (\omega t) $ At $ t=0,x=+A $ and $ t=\frac{T}{4},x=A\cos ( \frac{2\pi }{T}\times \frac{T}{4} )=A\cos (\pi /2)=0 $
Again $ t=\frac{T}{2},x=A\cos ( \frac{2\pi }{T}\times \frac{T}{2} )=A\cos \pi =-A $
We can see that, only graph (i) will satisfy the above results
