At the time t1 = 0, an object with a mass m = 7.51 kg passes through the origin with a velocity v1 = (5.21î − 2.21ĵ) m/s. At a time t2 = 2.00 s, the object is at the position r = (8.00î + 4.00ĵ) m. Assume that the force acting on the object during the time interval Δt = t2 − t1 is constant and determine the following. (a) the kinetic energy of the object at the time t1 J (b) the force acting on the object during the time interval Δt = t2 − t1 (Express your answer in vector form.) F = N (c) the work done on the object by the force during the time interval Δt = t2 − t1 J (d) the kinetic energy of the object at the time t2 J (e) the speed of the object at the time t2 m/s