Question

At time t=0 one particle is at maximum positive amplitude

Answer 1

The amplitude and time period for both particles are same and equal to A and T, respectively. At time t=0 one particle has displacement

Answer 2

Answer:

…I am sorry but somehow I feel the question is not complete. Still I will try and provide you with correct answer…

Explanation:

First I assume that you are speaking of the SHM (Simple Harmonic Motion). This type of motion is exhibited by a particle when moving along a line parallel to the x-axis. The point here as you have already mentioned time, so I think that its position as compared ot the time factor varies at any stage of time.

Now lets see you are speaking of its motion when t=0, this means that the particle is not stationary, as it is in motion (oscillations). This type of oscillation in general is termed  as equilibrium. And the mean position around which the particle oscillates, it is termed as its equilibrium position.

So here is t = 0, then x0 = 0.

Now, the next thing that you say is that the amplitude is maximum, that means that the displacement of the particle from its original mean position is said to be maximum. After this, if the value of t increases, then the amplitude of the particle from its means position would in fact decrease.

This means that the particle would in fact start to come much closer to its mean position or centre position.

Now you need to keep in mind that even at maximum amplitude, the displacement of the particle could in fact be positive or negative.

Now, you actually need to let me know what you want me to calculate…

Angular frequency, frequency, time period, or its acceleration. Let know.