A golf ball is hit off a tee at the edge of a cliff. Its x and y coordinates as functions of time are given by x = 19.9t and y = 4.08t ? 4.53t2, where x and y are in meters and t is in seconds.

(a) Write a vector expression for the ball's position as a function of time, using the unit vectors and . (Give the answer in terms of t.) r = _____ By taking derivatives, do the following. (Give the answers in terms of t.)

(b) obtain the expression for the velocity vector as a function of time

____ = V

(c) obtain the expression for the acceleration vector as a function of time

____ = a

(d) Next use unit-vector notation to write expressions for the position, the velocity, and the acceleration of the golf ball at t = 3.21 s.

____ = m ____ = m/s ____ = m/s2