At the time t1 = 0, an object with a mass m = 4.51 kg passes through the origin with a velocity v1 = (5.81i - 2.21j) m/s. At a time to = 2.00 s, the object is at the position r = (8.001 + 4.00j) m. Assume that the force acting on the object during the time interval At = t2 - t1 is constant and determine the following. (a) the kinetic energy of the object at the time t1 87.89 (b) the force acting on the object during the time interval At = t2 - t1 (Express your answer in vector form.) F = X See if you can use the kinematic equations to determine the acceleration of the object and then the force acting on the object during the time interval At = t2 - t1. N (c) the work done on the object by the force during the time interval At = t2 - t1 X See if you can write an expression for the work done on the object in terms of the force acting on the object and the subsequent displacement of the object. J (d) the kinetic energy of the object at the time to X What does the work-kinetic energy theorem tell us about the net work done on an object and its change in kinetic energy. How is the final kinetic energy related to the initial kinetic energy and the change in kinetic energy? J (e) the speed of the object at the time to X Knowing the mass and kinetic energy of an object, how may we determine the speed of the object? m/s