The displacement of a particle performing linear S.H.M is given by $x=6 sin(3 \pi t-5\pi/6)$ metre. Find the time at which the particle reaches the extreme position towards the left:

Two particles executing SHM of the same amplitude and frequency on parallel lines side by side. They cross one another when moving in opposite directions each time their displacement is $\dfrac{\sqrt{3}}{2}$ times their amplitude. The phase difference between them is:

একজন বালিকা একটি দোলনায় বসে দোল খাচ্ছে। বালিকাটি উঠে দাঁড়ালে দোলনকালের কি পরিবর্তন হবে? 

The time period of a simple pendulum is air is $T$. Now the pendulum is submerged in a liquid of density $\dfrac{\rho}{16}$ where $\rho$ is density of the bob of the pendulum. The new time period of oscillation is.

কোনো কণার স্পন্দন গতির সমীকরণ x=10 sin (6πt +2π)। কণাটির কম্পাংক কত?