Athin film of oil of thickness t is floating on water. the oil has index of refraction no = 1.4. there is air above the oil. when viewed from the air in the direction normal to the surface, there is constructive interference of reflected red light with l = 675 nm. find the minimum thickness t of the oil film that will give constructive interference of reflected light with l = 675 nm.

(a) assume the equation x = at^3 + bt describes the motion of a particular object, with x having the dimension of length and t having the dimension of time. determine the dimensions of the constants a and b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.) (b) determine the dimensions of the derivative dx/dt = 3at^2 + b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.)