UIGestures translated to velocity - iphone

Question

So I'm looking at some code and basically there are a row of images and you swipe on the row, and the card images move in the row according to the swipe. Like you give it a flick, and then it moves 5 cards down the list. You give it a small flick, then you move 1 card down the list. It also has the ability to enter a card number, like if you were starting at card 1, and wanted to go to card 52, you type in 52, and it scrolls through all the 51 cards to get to card 52 and stops. Both the swipe gesture, and goToCard code call the below method:
- (void)doAnimation {
double elapsed = CACurrentMediaTime() - startTime;
if (elapsed >= runDelta) [self endAnimation];
else {
[self updateAnimationAtTime:elapsed];
}
}
- (void)updateAnimationAtTime:(double)elapsed
{
int max = 52;
if (elapsed > runDelta) elapsed = runDelta;
double delta = fabs(startSpeed) * elapsed - FRICTION * elapsed * elapsed / 2;
if (startSpeed < 0) delta = -delta;
offset = startOff + delta;
}
It looks like the developer was trying to match physics velocity equation of
DeltaX = Vot + (1/2) accel * time^2
It works pretty good when I test it in that the card images speed up according to your swipe in the beginning, and then slows down as you get closer to the runDelta (endpoint).
There's another function that calls updateAnimationAtTime like this:
- (void)goToCard:(int)pos {
int max = 52;
startSpeed = sqrt(fabs(pos - startOff) * FRICTION * 2);
runDelta = fabs(startSpeed / FRICTION);
startTime = CACurrentMediaTime();
timer = [NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:#selector(doAnimation) userInfo:nil repeats:YES];
}
It looks like in the above function, the startSpeed is calculated like it would be in physics:
Vf^2 = Vo^2 + 2ug(Xf - Xi)
where u is the coefficition of friction and they are assuming gravity is equal to 1.
So the code works, but when the # of cards gets increased from 52 to 300, the animation looks funny since it's cycling through 300 cards to go from start to finish. I've never really implemented physics related stuff in code and was wondering if anyone had any suggestions or tips in how to change the code to still give the user the effect that we're cycling through all the cards, but not cycle through all of them when it goes past 50 as that's where the animation starts to look funny as it starts to spin so fast that the original effect of cycling through cards is lost.
Please let me know if anything needs to be clarified in my question. Thanks!