A delivery man starts at the post office, drives 35 km north, then 25 km west, then 50 km northeast, and finally 35 km north to stop for lunch. Use the analytical method to determine the following. (Assume the +x-akis is to the east and the +y-axis is to the north.) (a) Find his net displacement vector (in km). km (b) How far is the restaurant from the post office (in km)? (Give the straight-ine distance.) km (e) If he returns directly from the restaurant to the post office, what is his displacement vector (in km) on the return trip? fret km (d) What is his compass heading on the return trip? (Give your answer in degrees counterclockwise from the east axis.) * countercockwise from the east axis