Why does a wave take time to reach distant particles if forces act instantaneously?

[sadhu]

I have got a trouble with wave concept

suppose wave is passing through a medium ( let it ,just started)

suppose there are four points in the medium (particles)
A,B,C,D

as soon as A is disturbed even by an infinitesimally small distance , B experiences a forces (forces act instantaneously ) . time taken =0;
same happens from B to C
then C to D


time in each case is 0
so net time is 0;

but wave takes some time to reach D, I can't understand why that time gap is coming .as every thing is happening instantly.

 

[G01]

Why are you assuming the force from one particle is instantaneously felt by the next?

The fact is that the force is not instantaneously felt by the second particle.

 

[timon]

if i remember correctly, force is limited at the same speed as light

 

[sadhu]

that means every wave should have a speed of light