Ameteoroid is moving towards a planet. it has mass m = 0.78×109 kg and speed v1 = 4.1×107 m/s at distance r1 = 2.8×107 m from the center of the planet. the radius of the planet is r = 0.26×107 m. the mass of the planet is m = 4.4×1025 kg. there is no air around the planet. calculate the value of pe1, in joules

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

You can decrease the resistance of a length of wire by

In a hydrogen molecule there are a total of four charges, 2 protons in the two nuclei, and 2 electrons. how many unique charge-pairs are there (without double counting)?