Question

A body performs simple harmonic oscillation along the straight line ABCDE with C

Answer 1

For this question, let us take X= R sin wt U which is represented as potential energy.  After that, you need to go for the following calculation

B= U at D= (3/4)X(1/2)K(R^2)- (1/2)K(x^2)= X= (√3/2)R.  

Then D=2X= √3 R.After all the calculation in a reasonable manner, we have got this in the final stage.  Hence this is the answer to this question.