(a) A hotdog vendor named Sam is walking from the southwest corner of Central park to the Empire State Building. He starts at the intersection of 59th Street and Eighth Avenue, walks 3 blocks east to 59th Street and Fifth Avenue, and then 25 blocks south to the Empire State Building at the Corner of 34th Street and Fifth Avenue. Write his displacement vector in rectangular notation with units of "blocks." Orient the axes so positive y is to the north, and positive x is to the east. (b) A stockbroker named Andrea makes the same trip in a cab that gets lost, and detours 50 blocks south to Washington Square before reorienting and finally arriving at the Empire State Building. Is her displacement any different?

1 answer

a. Draw a straight hor. arrow pointing to the right. From the head of this arrow, draw a ver. arrow pointing downward to form a right angle. Draw the hypotenuse to form a right triangle. The length of the hyp. is the displacement from the starting point: Disp. = 3 - 25i. Magnitude = sqrt(3^2+25^2)

b. No. The displacement is the straight-line distance from starting point to destination which is the same in both cases.