Imagine for a minute that the Moon is held in its orbit about the Earth by electrical forces rather than by gravitation. What electrical charges -Q on the Earth and +Q on the Moon are necessary to hold the Moon in a circular orbit with a period of 27.3 days? The Earth-Moon distance is 384 000 km and the mass of the Moon is 7.35 1022 kg.
Question 2
An alpha particle (charge = +2e) is sent at high speed toward a gold nucleus (charge +79e). What is the electrical force acting on the alpha particle when it is at a distance of 2 10-14 m away from the gold nucleus? (e = 1.6 10-19 C)
The greenhouse effect: heat trapping by earth's atmosphere.
The Moon passing in front of the Sun, from the STEREO-B spacecraft.
The Phases of the Moon
Earth’s orientation
Humans are related to Earth’s other organisms
Earth 430 Million Years Ago