Which is faster???

[Rocket21]

Take two cars set up exactly the same. Except one weighs 5 oz and the other weighs 7 oz. Which one would be faster? Does the extra 2 oz added to the car make a huge difference? I know 7 oz is not legal I am curious for physics sake.

[Teeeman]

all things equal save you added 2oz to the heavier car and kept the COM at the same location...

7oz should be faster.

Doc Jobes software showed that the real huge improvement is 1-2oz range... adding weight really adds to the max velocity (no pun intended) you hit on the track...

up around 5-8oz things are leveling off...

but gains are still appreciable up to 16oz.

Past 16oz the asymptotic curve is pretty flat ... in theory you still make gains but they are tiny...

even for HUGE amounts of weight (i.e. 50lbs of it?)...

and as you get really heavy, the materials begin to be challenged (plastic and wood and soft steel).


-T

[ohiofitter]

up around 5-8oz things are leveling off...

but gains are still appreciable up to 16oz.

Teeeman if I'm not mistaking isn't it around 10 ounces that the weight starts to effect the wheel bore and put more friction to start slowing the cars down rather then speeding up....

[Stan Pope]

Rocket21,

Now that you know "what", the question for you to dig answers out for is "why?" You know, for instance, that many of the losses a PW racer faces are proportional to weight. The additional weight just increases the friction loss so that speed doesn't increase.

Since weight does make a difference, then some of the losses must be independent of weight and increase either not at all or much slower than weight.

For physics sake, your assignment is to make a list of those losses. (The first two should be easy, since we have talked about them before on the board.)