the speed of light equals its wavelength x its frequency - the equation is simply c=λf where f is in hz=sec^{-1}. mind my asking which is the true counterpart for frequency: hz as inverse second xor rote per minute (rpm)? they are not same. if it is hz then what stops me from putting V=xf instead of x=Vt? in my opinion speed of light over the frequency must be the wave length over the rotes or c x n = λ x f. the reason is simple: in General Physics I frequency is considered as inverse oscillatory period T = time for one rote. thereby f must be in rotes over second. but that alters the entire General Physics II.