Ikabot

Hi, I have a problem which I can't resolve. I would like some hints which could help me to resolve it. A Hall-effect probe operates with a 120-mA current. When the probe is placed in a uniform magnetic field of magnitude 0.080 T, it produces a Hall voltage of 0.700 microV. a) When it is measuring an unknown magnetic field, the Hall volage is 0.330 microV. What is the magnitude of the unknown field? b) The thickness of the probe in the direction of B is 2.00 mm. Find the density of the charge carriers, each of which has charge of magnitude e (electron). Thanks

There was some physicist who said that the volume of a planet (or another space body) doesn't matter because the force it exerts is the same if its volume is higher or smaller. For example, the force between Earth and Sun doesn't depend on the volume of Earth or Sun, only depends on their masses and the disance center-center. So... I don't remember who said this and what said exactly. So if someone know it, it would be vere nice from him to tell me :DD P.S.: I hope you to understand my poor English >.<

I'd like to know what do you think about sending our nuclear waste to the Sun? Nuclear waste are vey radioactive and dangerous for people and for the enviroment, so, let's take them out of Earth, and let's send them to the Sun. And there, they will be disintegrated because of the high temperature of the sun. What do yo think about that? Y want to listen your opinion! Thank you!