in SHMrestoring force have max. magnitude at same instant but they are out of phase and point in opposite directions. HOW?/?
For simple harmonic motion, the acceleration a = -Ï2x is proportional to the displacement, but in the opposite direction. Simple harmonic motion is accelerated motion. If an object exhibits simple harmonic motion, a force must be acting on the object. The force is
F = ma = -mÏ2x .
It obeys Hooke's law, F = -kx, with k = mÏ2.
Hope this helps.