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 7.2 m/s. during the second part, she rides for 36 minutes at an average speed of 5.1 m/s. finally, during the third part, she rides for 8.0 minutes at an average speed of 13 m/s.
a. how far has the bicyclist traveled during the entire trip?
b. what is her average velocity for the entire trip?

Answer 1

part a)

path of the cyclist consist of three parts

during the first part, she rides for 22 minutes at an average speed of 7.2 m/s. during the second part, she rides for 36 minutes at an average speed of 5.1 m/s. finally, during the third part, she rides for 8.0 minutes at an average speed of 13 m/s.

total distance in first part

$d_1 = 22*60 * 7.2 = 9504 m$

total distance in second part

$d_2 = 36*60 * 5.1 = 11016 m$

total distance in third part

$d_3 = 8 * 60 * 13 = 6240 m$

so total distance would be

$d = 9504 + 11016 + 6240 = 26760 m$

part b)

average velocity is given as

$v = \frac{displacement}{time}$

$v = \frac{26760}{(22 + 36 + 8)*60}$

$v = 6.76 m/s$

so average velocity is 6.76 m/s