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GatoGordo

GatoGordo

Active member
So i have basically become retarded, and i can't remember how to solve this problem for physics. I will give you some good karma, and i hope others will give you some of you help me out here. I need the answer as quickly as you can solve it, but it's not that hard, so it shouldn't take long. Here it is:

Imagine a ball rolling against friction. We don’t know the initial velocity but it

comes to a stop after 3.33 seconds after having rolled 6.75 meters. Use that information to find the initial velocity and the acceleration of the ball.

Try to use one of the three Galileans equations to solve it, because that is what we use.

 
Vo= 2.027 m/s = Initial Velocity

a= 0.85 m/s = Acceleration

X= Final distance

Xo= Initial Distance

V= FinalVelocity

X=Xo+ Vt

6.75=0+V(3.33)

V= 2.027 m/s

V=Vo + at

0= 2.027) + a(3.33)

a= 0.609 m/(s^2)

Hopefully I didn't mess anything up, I'd check the math again.
 
haha, don't sweat it. it's pretty simple, if someone taught it to you I'm sure you could learn those formulas pretty quickly. it's just "plug and chug" as all the teachers like to say.. just look at the variables in the equation and use the numbers in the question to find the missing variables. plug in and solve.
 
haha, if the acceleration is positive then the ball will never stop rolling, it will only speed up. gatogordo, are you given the friction coefficient of the ball?
 
word, negative acceleration then. maybe I messed up something and switched a sign somewhere. you don't need the friction coeff. to solve this one though because you have the time it took to stop etc. idk, I'm supposed to be studying for this damn wavelengths test here..
 
thanks, give to hoseph too for helping out as well!

yeah, physics can be fun but incredibly frustrating as well.

 
yea i should be studying for a wavelengths test right now too!!! haha physics can suck sometimes, especially when the teacher sucks like mine.
 
stuffs no fun, dont worry, you'll have a project end of the year that will save your grade....as long as its highschool.
 
It went pretty well! sorry to hear yours didn't. I was pretty happy because the rest of the tests haven't been too great and I feel like I knew this one. either way I don't know for sure until I get the test back.
 
i took the same test as mistaskia and it sucked balls. it was realy easy math but had all these detailed questions on interference and random stuff that you wouldnt know unless you read the chapter 5 mins before class. the problem is our teacher is nice he just doesnt teach sometimes and thinks we should magically know it
 
Physics is the ONLY class I've ever enjoyed in school. It teaches you about all this cool shit going on all around you. Hopefully you get a teacher that doesn't employ "plug and chug" then it might not be so fun. My teacher made it make sense and I understand why I use those formulas (especially when we take 3 weeks to derive all of them)

I can't stress enough for people who don't really like school, to take phyics. Its a great class
 
Dunno if you already submitted it or whatever, but this is wrong. The formula X=Xo+ Vt only works if there is no acceleration. It's basically Velocity = Distance / Time. The right formulas to use would be

V = Vo + A * T

X - Xo = Vo * T + (1/2) * A * (T)^2

You know everything except Vo and A, so solve using a system of equations. You should get Vo = 4.05 m/s and A = -1.217 m/s^2 .
 
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