Can someone answer the question below?

Solve the equation w^3 = 1,000 i honestly dont know how to punch this into a calculator pls

If f(x) = x+8 and g(x) = 4x- 3, find (f+g)(x)

Apinhole camera is made out of a light-tight box with a piece of film attached to one side and pinhole on the opposite side. the optimum diameter d(in millimeters) of the pinhole can be modeled by d=1.9[ (5.5 x 10^-4) l) ] ^1/2, where l is the length of the camera box (in millimeters). what is the optimum diameter for a pinhole camera if the camera box has a length of 10 centimeters