Question

During the middle of a family picnic, Barry Allen received a message that his friends Bruce and Hal needed to be saved. Barry promised his wife Iris that he would be back in exactly 5 minutes. From that that picnic location, Barry runs at a speed of 600 m/s for 2 minutes at a heading of 35° north of west to save Bruce. He then changed his heading to 30° west of north, slows down to 400 m/s and runs for 1 minute to save Hal. (The changes in speed are essentially instantaneous and not part of solving this problem). (a) Draw a physical representation of the displacement during Barry’s full trip. (b) Use the Related Quantities sense-making technique to compare Barry’s total distance traveled to the magnitude of his displacement. (c) What average velocity (magnitude and direction) does Barry need to return back to the picnic in order to keep his promise to Iris?

Answer 1