I Might Just Know What I'm Talking About
Join Date: Oct 2000
Location: C-ville, VA
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Re: OT - Random Physics Question
Still not buying it.
In one full rotation, the tire will go from a dead stop to full speed.
Now the full speed is the speed it needs to overtake the Jeep. If said Jeep has 20 inch tires, then the point "a" on the tire wil have to cover the circumfernece of the tire minus on half in a set period of time. Now the same Jeep at the same speed has a tire diameter of 44 inches, then the same point "a" will have to travel further to make the half rotation in the same set period of time.
mph is distance travled per period of time, so the point "a" on the second tire is having to travel further to reach the same spot in time thereby moving faster than the point "a" on the smaller tire. Is this not the reason gears work?
So the rock on the larger tire leaves at a higher speed than on a smaller tire. That is why I reason a need for tire diameter for this question. To say that the rock is going 70mph may be correct at only <u>one point</u> in the tires rotation. At any other time, the speed differencial (relative to itself) is always changing.
I have stated my argument, please respond as I love livly debate.
Oh yeah, I reread the BB post and it does have a similiar slant, but in the entire post, there isn't mentioned the difference made by tire hieght.