waves

2/k ?

the wave equation is f(x,t) = A2 - Acos(2wt - 2kx)2

wave welocity = w/k

for calculating particle velocity, let us fix a particular position (x=0 for convenience)

then f(t) = A2 - Acos(2wt)2

f'(t) = wAsin(2wt)

so, v_max (of particle) = wA = w/k

=> A = 1/k

asish,you are correct , it is 1/k.i hurriedly wrote sin²(ωt-kx) as 1-cos(ωt-kx)/2