A particle moves along the x-axis according to the equation x = 50t + 10t^2, where x is in meters and t is in seconds. Calculate (a) the average velocity of the particle during the first 3.0 s of its motion, (b) the instantaneous velocity of the particle at t = 3.0 s, and (c) the instantaneous acceleration of the particle at t = 3.0 s.