1. The problem statement, all variables and given/known data An objects position as a function of time is given by r=12ti+(15t-5.0t^2)jm, where t is time in seconds. A: what is the onject's position at t=2 s. B what is its average velocity in the interval from t=o to t=2.0s.C: what is its instantaneous velocity at t=2? 2. Relevant equations Derivative:12i+(15-10t) V=change in r/change t 3. The attempt at a solution A: simply plug 2 in for t in the original equation B:take the derivative of the problem and plug in 2 for t C: Dont really know . . .