A proton initially has v = 4.0i - 2.0j + 3.0k and then 4.0s later has v = -2.0i-2.0j+5.0k in meters per second. For that 4.0s, what are:a. the poton's average acceleration a avg in unit vector notation. b. the magnitude of the a avg. c. the angle between a avg and the positive direction of the x axis.