Respuesta :
Answer:Both A and B is true
Explanation:
Given system is friction less
Consider a system of spring mass-system with general displacement equation
[tex]x=A\sin \omega t[/tex]
where A=maximum amplitude
[tex]\omega [/tex]=frequency of oscillation
[tex]t=time[/tex]
[tex]v=A\omega cos\omega t[/tex]
Total Energy of the system is E=Potential Energy(U)+kinetic Energy(K)
At max amplitude
i.e. [tex]A=A\sin\omega t[/tex]
[tex]\omega t=\frac{\pi }{4}[/tex]
[tex]t=\frac{\pi }{4\omega }[/tex] [tex](T\cdot \omega =2\pi )[/tex]
where T = time period for one complete oscillation
[tex]t=\frac{T}{4}[/tex]
at [tex]t=\frac{T}{4}[/tex]
[tex]v=0[/tex]
thus [tex]k=0[/tex] and [tex]U=E[/tex]
i.e. Maximum at maximum amplitude
B.at mean position [tex]x=0[/tex]
[tex]\omega t=\pi [/tex]
[tex]t=\frac{T}{2}[/tex]
[tex]v=v_{max}[/tex] i.e. total Energy is equal to Kinetic energy and Potential Energy is zero
hence B is true.
