1. The problem statement, all variables and given/known data
Compute your average velocity in the following 2 cases: (a): You walk 73.2 m at a speed of 1.22 m/s and then run 73.2 m at a speed of 3.005 m/s along a straight line.
2. Relevant equations
this asks for average velocity which equals=change of x/change of t or xfinal-xinitial/tfinal-tinitial
isn't acceleration = change of velocity over/ change of time
so what do i do, because it gives me two velocities
LowlyPion
Aug28-08, 09:29 PM
1. The problem statement, all variables and given/known data
Compute your average velocity in the following 2 cases: (a): You walk 73.2 m at a speed of 1.22 m/s and then run 73.2 m at a speed of 3.005 m/s along a straight line.
2. Relevant equations
this asks for average velocity which equals=change of x/change of t or xfinal-xinitial/tfinal-tinitial
isn't acceleration = change of velocity over/ change of time
so what do i do, because it gives me two velocities
How long did it take you to accomplish the circuit? Vavg is defined as what? You know change of x, so ...?
afcwestwarrior
Aug28-08, 09:33 PM
Ok. I'm assuming that you add both of the velocities. 1.22 m/s+ 3.05 m/s=4.27m/s
My total distance was 73.2 m + 73.2 m=146.6 m
4.27m/s / 146.6 m=.0291268759 seconds
LowlyPion
Aug28-08, 09:41 PM
Ok. I'm assuming that you add both of the velocities. 1.22 m/s+ 3.05 m/s=4.27m/s
My total distance was 73.2 m + 73.2 m=146.6 m
4.27m/s / 146.6 m=.0291268759 seconds
I think you've used an invalid approach.
The sum of the velocities divided by the total distance is not equal to the time.
How long does it take to do the first leg - 73.2 m at 1.22 m/s?
afcwestwarrior
Aug28-08, 09:44 PM
It takes 60 seconds.
LowlyPion
Aug28-08, 09:47 PM
It takes 60 seconds.
OK. Now how long for the second leg?
afcwestwarrior
Aug28-08, 09:50 PM
It takes 24 seconds
LowlyPion
Aug28-08, 09:52 PM
Knowing total distance and total time now you are in position to calculate avg velocity. This is given by which of the equations you cited in your first post?
afcwestwarrior
Aug28-08, 09:56 PM
ok so it would be 73.2+73.2=146.4
146.4m/60s-24s=4.07m/s
afcwestwarrior
Aug28-08, 10:02 PM
wait a minute would i add the time together
LowlyPion
Aug28-08, 10:20 PM
wait a minute would i add the time together
Well I sure would. Not sure why you would subtract time in this case. You want total time.
You did post this didn't you?
...this asks for average velocity which equals=change of x/change of t ...