Question

A jogger runs in a straight line with an average velocity of 7.7 m/s for 4.5 minutes, and then with an average velocity of 2.8 m/s for 2.8 minutes. What is her total displacement? Answer in units of m.

Answer 1

total distance: 7.7*4.5*60 + 2.8*2.8*60 = 2549.4 m
total time: (4.5+2.8)*60 = 438 s

so, avg velocity is 2549.4/438 = 5.8 m/s