What is the wavelength of an earthquake wave if it has a speed of 11 km/s and a frequency of 7 hz?

Adouble-slit experiment is performed with light of wavelength 600 nm. the bright interference fringes are spaced 1.8 mm apart on the viewing screen.what will the fringe spacing be if the light is changed to a wavelength of 400 nm? ?

An electromagnet is a device in which moving electric chargers in a coil of wire create a magnet.whats one advantage of using electromagnetic in devices

How does the entropy of steam compare to the entropy of ice?