If `overset(vec)(F)` is force vector, `overset(vec)(v)` is velocity , `overset(vec)(a)` is acceleration vector and `overset(vec)(r)` vector is displacement vector `w.r.t.` mean position than which of the following quantities are always non-negative in a simple harmonic motion along a straight line ?

Options

A. `overset(vec)(F).overset(vec)(a)`
B. `overset(vec)(v).overset(vec)(r)`
C. `overset(vec)(a).overset(vec)(r)`
D. `overset(vec)(F).overset(vec)(r)`

Answer

A

Explanation

since all collision are elestic and total energy is conserved
Time period of motion of right block is `t_(1) = (2L)/(v)`.
Time period of motion of left block is `t_(2) = (1)/(2)2pisqrt((m)/(2k))`
So. Total time period `= (2L)/(v) + (1)/(2) `