The radius of a typical human eardrum is about 4.15 mm. calculate the energy per second received by an eardrum when it listens to sound that is at the threshold of hearing, assumed to be 1.20e-12 w/m2

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.

The particles that are found in the nucleus of an atom are

At the negative terminal of the battery the electron has electric potential energy. what happens to this energy as the electron jumps from the negative to the positive terminal?