8. A 4 kg particle moves along the x-axis. Its position varies with time according to x = t + 2t, where x is in m and t is in s. Find "approximately" the work done on the particle in the interval t = 0 to t = 2 s. a. O J b. 1250 J c. 125 J d. 1200 J e. 50 J 3