Question

A bus travels 280 km south along a straight path with an average velocity of 88 km/h to the south. The bus stops for 24 min, then it travels 210 km south with an average of 75 km/h to the south.
a. How long does the total trip last?
b. What is the average velocity for the total trip?

Answer 1

a. Okay, to find the total time split the trip into three parts and solve for time in each. Then add the three parts together to find the total time. part 1: Dt = Dx/ vavg = (280km)/(88km/h) = 3.182 h part 2: Dt = (24min)(1h/60min) = .4 h part 3: Dt = Dx/ vavg = (210km)/(75km/h) = 2.8 h total time = 3.182 h + .4 h + 2.8 h = 6.38 h or 6 h 23 min b. To find the average velocity of the total trip, use the formula vavg = Dx/Dt , and for Dx and Dt use the time and displacement of the total trip. vavg = (280km + 210km)/(6.38h) = 77 km/h