A bicyclist makes a trip that consists of three parts, each in the same direction (due north) along a straight road. During the first part, she rides for 22 minutes at an average speed of 6.50m/s. During the second part, she rides for 36 minutes at an average speed of 4.30m/s. Finally, during the third part, she rides for 8.0 minutes at an average speed of 13.7m/s. How far has the bicyclist traveled during the entire trip?

Question

A bicyclist makes a trip that consists of three parts, each in the same direction (due north) along a straight road. During the first part, she rides for 22 minutes at an average speed of 6.50m/s. During the second part, she rides for 36 minutes at an average speed of 4.30m/s. Finally, during the third part, she rides for 8.0 minutes at an average speed of 13.7m/s. How far has the bicyclist traveled during the entire trip?
 
b). What is her average velocity for the trip?

Henry · Accepted Answer

Convert min. to seconds:
t1 = 22min * 60s/min = 1320 s.
t2 = 36min * 60s./min = 2160 s.
t3 = 8min * 60s/min = 480 s.

a. D = V1*t1 + V2*t2 + V3*t3.
D = 6.5*1320 + 4.30 * 2160 + 13.7*480 =
24,444 m. = Total dist. traveled.

b. T = t1 + t2 + t3.
T=1320 + 2160 + 480=3960 s.=Tot. time.
Vavg = D/T = 24444m/3960s = 6.17 m/s.