: > v(t) = sin(1000*t) : >

: > where t is the time : >

: > Isn't this expression, strictly speaking, incorrect? How can we : > find the sine of a time quantity? Shouldn't we have a constant : > in there as well with T^-1 dimension to solve this? : : It depends on how the symbols are used. If you say the time t is in : seconds, then t has a dimension; if you say the time is t seconds, : then t is dimensionless (it just says how many seconds you have). : Others have already responded by indicating that the 1000 may be : shorthand for 1000 radians per second (in which case t had better have : a dimension). Of course, you are still left with the fact that w = : 1000*t is in radians, so still has a dimension! : : R.G. Vickson : : >

: > For example: : >

: > v(t) = sin(1000***k***t) : >

: > where k a constant with units 1/s. :

v(t) = V.sin(omega.t) It may be that V is what he's missing.