A film of oil lies on wet pavement. The refractive index of the oil exceeds that of the water. The film has the minimum nonzero thickness such that it appears dark due to destructive interference when viewed in visible light with wavelength 643 nm in vacuum. Assuming that the visible spectrum extends from 380 to 750 nm, what is the longest visible wavelength (in vacuum) for which the film will appear bright due to constructive interference? Number Units

A piece of metal is placed on top of a 2.0 - kg wooden block (mass density = 562 kg/m³) piece. UseArchimedes' principle to calculate the mass (in kg) of copper if the top of the wood surface is exactly at thewater's surface?

A filmmaker wants to achieve an interesting visual effect by filming a scene through a converging lens with a focal length of 50.0 m. The lens is placed betwen the camera and a horse, which canters toward the camera at a constant speed of 7.9 m/s. The camera starts rolling when the horse is 36.0 m from the lens. Find the average speed of the image of the horse (a) during the first 2.0 s after the camera starts rolling and (b) during the following 2.0 s.