Asked by Kay
A car travels a straight road at 140 km/h for 30 min then at 90 km/h for 10 min. It then reverses and goes at 90 km/h for 20 min.
a) Find the average velocity for the entire trip.
b) Find the average speed for the entire trip.
a) Find the average velocity for the entire trip.
b) Find the average speed for the entire trip.
Answers
Answered by
Damon
30 min = .5 h
10 min = 1/6 h
20 min = 1/3 h
=================
d = 140*.5 + 90/6 + 90/3
(it went 90 for a total of 1/2hour???? typo I bet)
average speed = d /total time
the way you wrote it the total time is one hour, but I doubt it.
10 min = 1/6 h
20 min = 1/3 h
=================
d = 140*.5 + 90/6 + 90/3
(it went 90 for a total of 1/2hour???? typo I bet)
average speed = d /total time
the way you wrote it the total time is one hour, but I doubt it.
Answered by
Reiny
The three legs of the trip are
70 km , 15 km , and 30 km for a total time of 1 hour
average velocity = (70 + 15 - 30)/1 = 55 km/h
average speed = (70+15+30)/1 = 115 km/h
velocity involves both magnitude and direction.
Since the direction was reversed for the last part, I used -30
70 km , 15 km , and 30 km for a total time of 1 hour
average velocity = (70 + 15 - 30)/1 = 55 km/h
average speed = (70+15+30)/1 = 115 km/h
velocity involves both magnitude and direction.
Since the direction was reversed for the last part, I used -30
Answered by
Damon
I did not see the reversal of direction