cho điện tích q1=2nc và q2=-8nc đặt tại A và B cách nhau 20cm . Tìm điểm chứa q0=3nc để q0 nằm cân bằng

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?

Which describes increasing the efficiency of energy resource

Calculate a pendulums frequency of oscillation (in hz) if the pendulum completes one cycle in 0.5s.