A metal sphere with radius ra = 1.20 cm is supported on an insulating stand at the center of a hollow, metal, spherical shell with radius rb = 9.20 cm . Charge +q is put on the inner sphere and charge −q on the outer spherical shell. The magnitude of q is chosen to make the potential difference between the spheres 490 V , with the inner sphere at higher potential.
Calculate q.

Asatellite that goes around the earth once every 24 hours iscalled a geosynchronous satellite. if a geosynchronoussatellite is in an equatorial orbit, its position appearsstationary with respect to a ground station, and it is known as ageostationary satellite find the radius rof the orbit of a geosynchronous satellite that circles the earth.(note that ris measured from the center of the earth, not the surface.) you mayuse the following constants: the universal gravitational constant g is 6.67 \times 10^{-11}\; {\rm n \; m^2 / kg^2}. the mass of the earth is 5.98 \times 10^{24}\; {\rm kg}. the radius of the earth is 6.38 \times 10^{6}\; {\rm m}.