What is the equation to find wavelength of red light with a frequency of 4 x 10^14

Global warming will produce rising sea levels partly due to melting ice caps but also due to the expansion of water as average ocean temperatures rise. to get some idea of the size of this effect, calculate the change in length of a column of water 1.00 km high for a temperature increase of 1.00ºc. note that this calculation is only approximate because ocean warming is not uniform with depth. (answer in ×10^{-3} −3 m)

What type of force holds atoms together in a crystal?

The index of refraction of the oil is 1.20. what is the minimum thickness t of the oil slick at that spot?