Asked by Dakkota
A car makes a trip due north for three-fourths of the time and due south one-fourth of the time. The average northward velocity has a magnitude of 25 m/s, and the average southward velocity has a magnitude of 32 m/s. Taking northward to be the positive direction, what is the average velocity for the trip?
Answers
Answered by
Damon
pick some times that meet the criterion
north for 30 seconds, south for 10 seconds , total time = 40 seconds
distance north from start = 25*30
then back 32*10
total distance north (displacement vector, not distance traveled) = 25*30 - 32*10
so
Vaverage = (25*30 - 32*10)/40
= (75 - 32)/4
= 10.75 m/s
north for 30 seconds, south for 10 seconds , total time = 40 seconds
distance north from start = 25*30
then back 32*10
total distance north (displacement vector, not distance traveled) = 25*30 - 32*10
so
Vaverage = (25*30 - 32*10)/40
= (75 - 32)/4
= 10.75 m/s