Q. A uniform 1.3-kg rod that is 0.80 m long is suspended at rest from the ceiling by two springs, one at each end of the rod. Both springs hang straight down from the ceiling. The springs have identical lengths when they are unstretched. Their spring constants are 60 N/m and 35 N/m. Find the angle that the rod makes with the horizontal.
Q. A barbell is mounted on a nearly frictionless axle through its center. The low-mass rod has a length d = 0.30 m, and each ball has a mass m = 0.2 kg. At this instant, there are two forces of equal magnitude F applied to the system, with the directions indicated, and at this instant the angular velocity is 103 radians/s, counterclockwise, and the angle θ = 28°. In the next 0.007 s, the angular momentum relative to the center increases by an amount 4.2 × 10-4 kg · m2/s. What is the magnitude of each force?