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How does one go about computing gas mileage in reverse? :?
Dang, beat me to it!WayneBruce said:no, reverse gas mileage is egaelim sag.
Better yet, does it decrement???? Perhaps when you drive in reverse the car "youthens" like Merlin in the T.H. White version of Arthurian legend.KTPhil said:Does the Prius odometer increment while driving in reverse? Buehler? Anyone?
I sure hope I take a course in Physics to understand this!!mrv said:well, if you go fast enough in reverse you get a positive velocity (positive speed on the spedometer, and not a negative number).
Since velocity = distance/time, and velocity and time are positive values (time isn't going backwards!), the distance must also be positive.
(BTW: if you want to show off the torquiness of the electric motor, find a nice safe area with some good distance, and floor it in reverse! I get chicken in the high teens on the spedometer, but...)
Not so. Velocity is a vector, so it has both a magnitude and a direction. If you define forward motion as the positive direction, then reverse would indeed result in a negative velocity. Of course, if you define reverse as the positive direction, then going forward would result in a negative velocity.mrv said:well, if you go fast enough in reverse you get a positive velocity (positive speed on the spedometer, and not a negative number).
Since velocity = distance/time, and velocity and time are positive values (time isn't going backwards!), the distance must also be positive.
(BTW: if you want to show off the torquiness of the electric motor, find a nice safe area with some good distance, and floor it in reverse! I get chicken in the high teens on the spedometer, but...)
Can you translate this into "English" for us "knotheads"?bsoft said:Not so. Velocity is a vector, so it has both a magnitude and a direction. If you define forward motion as the positive direction, then reverse would indeed result in a negative velocity. Of course, if you define reverse as the positive direction, then going forward would result in a negative velocity.mrv said:well, if you go fast enough in reverse you get a positive velocity (positive speed on the spedometer, and not a negative number).
Since velocity = distance/time, and velocity and time are positive values (time isn't going backwards!), the distance must also be positive.
(BTW: if you want to show off the torquiness of the electric motor, find a nice safe area with some good distance, and floor it in reverse! I get chicken in the high teens on the spedometer, but...)
Velocity is not distance over time. Velocity is a change in displacement over a change time, and, as it is a vector, displacement can indeed be negative.
Speed is a scalar, so it is always positive, regardless of direction.