An object is hanging by a string from the ceiling of an elevator. the elevator is moving upward with a constant speed. what is the magnitude of the tension in the string?

How would you place two electrons on a sphere of radius r so that the electrostatic potential energy is minimized. how would you place three electrons to solve the same problem.

Solar cell a produces 100 joules of energy, when a light source is shown on it for 3 minutes. solar cell b produces 200 joules of energy when the same light source is shown on it for 5 minutes. which solar cell works better? a) solar cell b, because it produces more energy. b) solar cell b, because it generates more power. c) solar cell a, because it produces energy quicker. d) solar cell a, because it generates a greater wattage. eliminate

1point) a skydiver weighing 130 lb (including equipment) falls vertically downward from an altitude of 14,000 ft and opens the parachute after 20 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.85|v|0.85|v| when the parachute is closed and is of magnitude 17|v|17|v| when the parachute is open, where the velocity vv is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. find the speed of the skydiver when the parachute opens. speed is 150.6121788 ft/s find the skydiver's height when the parachute opens. height is 2338.98591 ft find the limiting velocity vlvl after the parachute opens. (think about whether this should be positive or negative.) vl=vl= 7.647 ft/s