You guys seem to like these riddles so here it goes. You place a perfectly spherical ball on a 2m ramp with an incline of 65 degrees. Both the ramp and the ball are frictionless. At what velocity is the ball rolling when it reaches the bottom of the ramp?
Since I used MathType for all of my equasions, I typed it in MS Word and saved it as a .html page:
http://www.sidoh.org/school/Physics/Physics_Problem.htm
Sidoh, gimme mathtype.
Anyways, numbers confirmed.
Quote from: rabbit on December 06, 2005, 07:53:17 PM
Sidoh, gimme mathtype.
Anyways, numbers confirmed.
http://sidoh.dark-wire.net/Files/MathType52Setup.exe
It's a free trial edition. I never found a crack that worked, so I just used the toned down version that it reverts to after 30 days. It works fine for almost everything unless you're a seroius mathematician. :)
I'll move this to 'Solved Riddles' once Nate confirms it's the correct answer. I'm still a bit eery on the whole "frictionless" thing.
Wait... did you just do his homework...?
Sidoh got it right. Although all that work wasn't required. The ball will slide down the ramp not roll if it is frictionless.
Quote from: Nate on December 06, 2005, 09:12:05 PM
Sidoh got it right. Although all that work wasn't required. The ball will slide down the ramp not roll if it is frictionless.
Then the answer would be different. If rotational kinetic energy exists, the center-of-mass magnitude will decrease.
Here's the correct answer (though I like my other one more since it's more practical):
(http://sidoh.dark-wire.net/upload/files/2IVMQE2BWA-a882a9411f5e1b8c.jpg)
Saying it was frictionless took all the fun out of it. :(
Quote from: Nate on December 06, 2005, 09:12:05 PM
Sidoh got it right. Although all that work wasn't required. The ball will slide down the ramp not roll if it is frictionless.
Damnit, I was going to say it would slide :)
Quote from: iago on December 06, 2005, 10:54:20 PM
Damnit, I was going to say it would slide :)
I kind of figured it would, but I couldn't pass up on the oportunity to play with rotational kinetic energy. :)
hopefully my phisics class next year eases into this :)
Quote from: Toweliex86] link=topic=4041.msg43049#msg43049 date=1133929088]
hopefully my phisics class next year eases into this :)
This isn't hard stuff, it's all algebra!
Moving this to solved.
There are other interesting problems like this. You don't have to ignore friction, either! It makes things a lot more interesting. :)
One of the problems we did today was how much thermal energy is generated from a book that is pushed at a certain velocity and stops after a certain distance. It was pretty interesting seeing the numbers behind friction. :)
Quote from: Sidoh on December 06, 2005, 09:31:02 PM
Saying it was frictionless took all the fun out of it. :(
For you maybe but its quite enjoyable for me to watch you do all that work for nothing.
Quote from: Nate on December 07, 2005, 03:21:06 PM
For you maybe but its quite enjoyable for me to watch you do all that work for nothing.
Not for nothing!
It was a good representation of rotational kinetic energy! :]
Btw, everybody who posts a physics problem should give it a good name. I'm never sure which physics problem is which, so I usually don't look at any of them :)
ok I could name this, "What is the rotational velocity of a perfect sphere travelling down a ramp in a frictionless world?". You would click on that? I think not...
Quote from: Nate on December 08, 2005, 07:18:31 PM
ok I could name this, "What is the rotational velocity of a perfect sphere travelling down a ramp in a frictionless world?". You would click on that? I think not...
Then the riddle would be entirely too easy. All you'd have to say is 0 and you'd be correct; no math involved! Booorrrinngg... :(
You could name it "Ramp + Sphere - Friction = ?" or something like that. You just have to be creative. :)
or just "Physics: rolling ball"