## ← 06ps-03 Rollercoaster with Friction

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Showing Revision 1 created 10/27/2012 by Amara Bot.

1. This problem is very similar to the previous problem,
2. but now we're going to add a bit of friction.
3. So now let's say that we have a hill of height of 45 m
4. and again we have our car which will go down the track through the loop and continue on.
5. Remember, the car needs to be going at least 10 m/sec as it goes through the top of the loop.
6. This question isn't so much about designing a roller coaster.
7. Here, it's already designed. Now, I want to know about maintaining a roller coaster.
8. Let's say after expecting the track, one of your maintenance workers finds that,
9. actually, this region of track which I've highlighted in black,
10. has gone a bit rusty and as a result, it's not so smooth.
11. Now, instead of sliding smoothly, the car grinds a little bit.
12. Clearly, this is probably not a good thing.
13. Just how much friction could there be to still allow the car to make it through this loop?
14. The question is what the maximum frictional force and remember there's only friction over this 20 m
15. the rest of the track, we're assuming is still nice and smooth.
16. What's the maximum force that would still allow the car to make it through this loop?