a) What is the momentum of a 1.20 x 10* kg truck whose velocity is 50.0 m/s? b) What velocity must a 6000 kg truck attain in order to have the same momentum? c) What velocity must it attain to have the same kinetic energy?A steel ball of mass 0.514- kg is fastened to a cord 68.? cm long and is released when the cord is horizontal. At the bottom of its path, the hall strikes a 2.6Ukg steel block initially at rest on a frictionless surface. The collision is elastic. Find [a] the speed of the ball and (b) the speed of the block, both just after the collision