3. Which of the following equations are dimensionally correct? (a)`v_f = v_i + ax` (b)`y=(2m)cos(kx)`,where `k=2m^-1`
match SI unit
SI unit of `v` is `m//s` SI unit of `x` and `y` a `m` SI unit of `a` is `m//s^2` (a) `m//s = m//s + m//s^(2)` `m//s = m//s + m^2//s^2` which cannot match. (b) `m = (2m)(cos(2m^(-1)times(m))` `=>m = m cos(2)` `=> m = m` which is dimensionally correct.