In the relation y=rsinωt-kx, the dimensional formula of ω/k are
M0L0T0
M0L1T-1
M0L0T1
M0L1T0
Given, y=rsinωt-kx
where, ωt=angle
∴ ω=1T=T-1 angle is dimensionless
Similarly kx = angle
∴ k=1x=L-1
ωk=T-1L-1=LT-1