physics
posted by anon on .
A car travels along a straight stretch of road. It proceeds for 15 mi at 51 mi/h, then 28.2 mi at 44 mi/h, and finally 36.4 mi at 39.3 mi/h.
What is the carâ€™s average velocity during
the entire trip?
Answer in units of mi/h

D = 15 + 28.2 + 36.4 = 79.6mi = Total distanced traveled.
T = 15mi/51mi/h + 28.2mi/44mi/h + 36.4mi/39.3mi/h = 1.86h.
Vavg. = d / t = 79.6 / 1.86 = 42.8mi/h.