When a 4kg mass is hung vertically on a light spring, the spring stretches 2.5cm. a.) how far will the spring stretch if an additional 1.5kg mass is hung on it? b.) if the 4 kg mass is removed, how far will the spring stretch if a 1.5 kg mass is hung on it? c.) how much work must be done on the spring to stretch the same spring 4 cm from its equilibrium position?

Two manned satellites approaching one another at a relative speed of 0.550 m/s intend to dock. the first has a mass of 2.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. assume that the positive direction is directed from the second satellite towards the first satellite. (a) calculate the final velocity after docking, in the frame of reference in which the first satellite was originally at rest.(b) what is the loss of kinetic energy in this inelastic collision? (c) repeat both parts, in the frame of reference in which the second satellite was originally at rest. final velocity(d) loss of kinetic energy = ?