A force F-(8.85-4.75t j) N, with t in units of s, is applied to a 2.00 kg object initially at rest. (a) At what time (in s) will the object be moving with a speed of 15.0 m/s? (Round your answer to at least two decimal places.) (b) How far (in m) is the object from its initial position when its speed is 15.0 m/s? (c) What is the total displacement (in m) through which the object traveled at this time? (Express your answer in vector form.)