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 = (displacement)/(time)`

`v = (26760)/((22 + 36 + 8)*60)`

`v = 6.76 m/s`

so average velocity is 6.76 m/s