What is the energy of an electromagnetic wave that has a frequency of 5.0 x 10 ^ 5 Hz ? Use the equation E = hf, where h = 6.626 x 10 ^ - 34 J•s

The electric field between square plates of a parallel-plate capacitor has magnitude e. the potential across the plates is maintained with constant voltage by a battery as they are pulled apart to twice their original separation, which is small compared to the dimensions of the plates. the magnitude of the electric field between the plates is now equal to a)e b)e/4 c)e/2 d)4e e)2e

The average density of the planet uranus is 1.27 103 kg/m3. the ratio of the mass of neptune to that of uranus is 1.19. the ratio of the radius of neptune to that of uranus is 0.969. find the average density of neptune.

What was the first instrument to ever record an earthquake?