Answer:

Step-by-step explanation:
given,
Amplitude ,A= 20 cm
distance between distance between two particle,y = 20 cm
Let equation of two SHM be x = A sin (ωt) and x = A sin (ωt + a)
where A is amplitude , ω is angular frequency and a is the phase difference.
now,
Distance between two particle at time t
y = A(sin(ωt+a)- sin (ωt))
using identity


for maxima

maximum distance






hence, the phase difference between the two particle is equal to
