A wave takes 2 seconds to reach the end. what is the frequency of the wave?

-amplitude: 1.5 m
-wavelength: 5m

Study the diagram showing the range of temperature in the earth’s layers. which temperature most likely corresponds to the asthenosphere? 1,613°c 2,521°c 3,628°c 6,217°c

Glass is transparent to visibile light under normal conditions; however, at extremely high intensities, glass will absorb most of the light incident upon it. this works through a process known as multiphoton absorption. in this process, several photons are absorbed at the same time. if very intense light whose photons carry 2ev of energy is shined onto a material with a band gap of 4ev, that light can be absorbed through two-photon absorption, because two photons have the right amount of energy to bridge the band gap. what is the minimum number of photons of 800-nm light that are needed to equal or exceed the band gap of fused silica glass

Why don't you see your reflection in water with waves or repples