Q. Two balls of mass 0.5 kg and 0.8 kg are connected by a low-mass spring. This device is thrown through the air with low speed, so air resistance is negligible. The motion is complicated: the balls whirl around each other, and at the same time the system vibrates, with continually changing stretch of the spring. At a particular instant, the 0.5 kg ball has a velocity ‹ 6, -5, 3 › m/s and the 0.8 kg ball has a velocity ‹ 4, 3, 7 › m/s.
Q. A spring stretches 4.1 cm when a 11 g mass is hung from it. If a total mass of 25 g attached to this spring oscillates in simple harmonic motion, calculate the period of motion.