Find v(t), a(t), T(t), and N(t) (if it exists) for an object moving along the path given by the vector-valued function r(t). (If an answer is undefined, enter UNDEFINED.) r(t) = 7ti - 8tj V(t) = a(t) = TO= N(t) = Use the results to determine the form of the path. O straight line O hyperbolic O quadratic O sinusoidal Is the speed of the object constant or changing? O constant O changing O can not be determined