You and two friends apply a force of 425 n to push a piano up a 2.0 m long ramp. if lifting the piano straight up requires 1700 n of force, what is the mechanical advantage of the ramp?

Explain the doppler effect in terms of frequency, wavelength, and speed.

What is the fate of the electrons that interact with a specimen in an electron microscope?

Imagine you had to physically add electrons, one at a time, to a previously neutral conductor. you add one electron very easily, but the second electron requires more work. in your initial post to the discussion, explain why this is. also, what happens to the work needed to add the third, fourth, fifth, and subsequent electrons