#3a) A spring with hooke's constant 2.1 MM runs horizontally and is attached to a block of mass 8.4 kg which can slide on a frictionless surface. Initially the block has a speed of zero and the spring is compressed 4.8m from its rest length. What is the speed of the block at the moment the spring has returned to its rest length? Correct: 2.4 mls #Sb) A sphere of mass m = 2.0 kg and radius 0.40 m rolls (without friction and without slipping) down an incline a vertical distance h = 3.5 m. Given that the rotational inertia of the sphere is J: 33 mrz, what is the rotational velocity w of the sphere when it reaches toe bottom of the incline. 4) If closed system consists of two objects name object A and object B, the masses of object A and object B are 10 kg and 12 kg respectively and in an inertial reference frame the velocity vectors before the object collide are (1.1 m/s , 2.2 m/s) and (3.3 m/s, -4.4 m/s), respectively, then what is the velocity of the objects after they collide if they stick together after the collision?2. A block of mass 5.0 kg is on an incline that makes an angle of 45 with the horizontal. The coefficient of kinetic friction between the block and the incline is 0.20. A string pulls on the block. The string runs parallel to the incline, then over a (approximately frictionless and inertia free) wheel at the end of the incline, then down to an otherwise free hanging triangular object of mass 100 kg. What is the magnitude of the acceleration vector of the block in an inertial reference frame with origin fixed with respect to the tip of the incline? Note: You must specify the axes for the coordinate systems you use. Correct quantity: 8.9m