its motion is not at first place means what? in ques. 1.
in ques 13 formula u took formula T= 2(pi) root(l/g) can i also use T=2(pi) root(I/mgl)?
in ques 13 you dont know the value of I to use that formula and it is applicable only for physical pendulums as given in HCV
What is the equation of plane progressive wave