If 10 waves pass a point each second and their wavelength is 30m, what is their speed?​

What produces light and all other electromagnetic waves? a) the photoelectric phenomena b) heated metals c) charged particles d) radioactive samples (pls explain if you can : )

Pls pls pls pls ! describe, in your own words, how you found the epicenter of the earthquake.

Standing side by side ,you and a friend step off a bridge at different times and fall for 1.6s to the water below. your friend goes first, and you follow after he has dropped a distance of 2.0m. when your friend hits the water, is the seperation between the two of you 2.0m or more than 2.0m? verify your answer with a calculation.