An ion with a charge of +3.2 x 10−19 C is in region where a uniform electric field of 5 x 104. V/m is perpendicular to a uniform magnetic field of 0.8 T. If its acceleration is zero then its speed must be:

What are the factors that affect the resistance of a wire?

Which component of the earth’s atmosphere is decreased due to photosynthesis?

Two identical stars with mass m orbit around their center of mass. each orbit is circular and has radius r, so that the two stars are always on opposite sides of the circle. (a) find the gravitational force of one star on the other. (b) find the orbital speed of each star and the period of the orbit. (c) how much energy would be required to separate the two stars to infinity?