A brick mason is on a steep roof repairing a chimney and drops a brick. If the brick slides down the roof and leaves the edge of the roof with the velocity v = (3.00 m/s)î − [(5.00 m/s) + (9.80 m/s2)t]ĵ, determine the displacement of the brick from the edge of the roof at a time t = 0.315 s after it leaves the edge of the roof.

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?