200 Hz = 200 cycles per sec
<span>1 cycle, the period = 1/200 = 0.005 seconds, or 5 milli seconds.</span>
Light travels as transverse waves and faster than sound. It can be reflected, refracted and dispersed. Ray diagrams show what happens to light in mirrors and lenses. Eyes and cameras detect light.
Answer:

Explanation:
When the block is displaced by x units
F= spring force
two springs are connected parallel

Writing Newtons second law, F = ma


a= x" ( differentiating x w.r.t time twice)

this the standard form of equation of oscillation spring mass system
This is the differential equation, x'' means that double differentiation of x , i.e, x'' is acceleration
since, Period 
therefore,
