# Search results

1. ### T-butyl vs. isopropyl subsitutions

Homework Statement T-butyl chloride can undergo substitution reaction to create C4H9OH, but isopropyl chloride cannot. Why is this? Homework Equations The Attempt at a Solution I'm guessing it has to do with the extra carbon. Maybe since it is a secondary halide, the substitution...
2. ### Substance decrease by factor of 100? (radioactivity)

Yes, I just forgot to put it in. Thanks for your help :)
3. ### Principal Quantum number by size?

Alrighty, thank you very much :)
4. ### Substance decrease by factor of 100? (radioactivity)

Ok I think I got it: N(o)/100 = N(o)e-kt 1/100 = e-kt ln(1/100) = e-kt ln(1/100) = -[(ln2)/8](t) 53.1 days = t
5. ### Principal Quantum number by size?

So I'm right? The answer is just 97? I thought the principal quantum numbers (n) only go up to like 5 or 6 or something like that though.
6. ### Substance decrease by factor of 100? (radioactivity)

Homework Statement Radioactive iodine (131-I) has a half life of 8 days. How long does it take for iodine to be reduced by factor of 100? Homework Equations N(t)=N(o)e-kt k=ln100/t1/2 The Attempt at a Solution N(t)=N(o)e-kt N(t)/N(o)=e-ln(100/8)t Now I'm stuck. I would...
7. ### Principal Quantum number by size?

Homework Statement What is the value of the principal quantum number for a hydrogen atom to have a size of one micron? Homework Equations r=(5.3x10-11)(n2) r=1x10-6/2=5x10-7 The Attempt at a Solution 5x10-7=(5.3x10-11)(n2) 97.1 = n How is this possible? lol Maybe it's more complicated...
8. ### Charge on each mass?

Alrighty, thanks alot :)
9. ### Charge on each mass?

Well I don't know what to do then lol.
10. ### What is electric field problem?

So then the final answer is 3.6Coulombs?
11. ### What is electric field problem?

I posted it above ^ you didn't say if its correct or not lol.
12. ### What is electric field problem?

Don't you divide 2mm by 100 twice to get to m? Yes, A is 0.36m. They give the dimensions of the plates as .6mx.6m Yup, that's what they give in the question. It says charge density is 10 Coulombs/m2
13. ### Charge on each mass?

Nope, I double-checked the problem and I wrote it exactly the same. Is it possible we can used substitution? Ex, solve for q and then plug it back in to solve for r.
14. ### What is electric field problem?

Ooooooh I see, thanks, you made that really clear. So, E = (1.13 x 1011)(10) = 1.13x1012 Coulombs/m2 b) V = EL = (1.13x1012)(.0002m) = 2.26x108Volts c) I'm gonna attempt this one and say that since you said E = (1.13 x 1011)(Q/A), then: 1.13x1012=(1.13x1011)(Q/.36) 27.8 coulombs =...
15. ### What is electric field problem?

a) Well it gives 10 Coulombs/m2 which equals Q/A, so how do I relate this to E=1.13x1011 Q/A? b) V=(answer in A)(.00002m) c) I still don't quite understand
16. ### Charge on each mass?

Alright so let me attempt this: F=mg=(1)(9.8)=9.8. This can then be used: F=Kq1q2/r2 9.8=(9x109)(q1q2)/r2, but then I'm still confused with what r is. Is it what I said?
17. ### What is electric field problem?

Homework Statement Two uniform plates have a uniform charge density of 10 Coulombs/m2. The plates have dimensions of 0.6x0.6 m2 and are seperated by 2mm a) The electric field (V/m) between the two plates is given by E=1.13x1011 Q/A where Q is the charge in Coulombs on one plate and A is the...
18. ### Charge on each mass?

I believe r in the first equation is between the centr of the earth and the object, so would it just be as if the object is on the surface of the earth. And the 2nd equation is the distance between the two objects.
19. ### Charge on each mass?

Homework Statement Two equally charged 1g masses repel each other. The lower mass is held fixed. a)What is the charge on each mass for the Coulomb force to balance the gravitational force of the Earth on the upper mass? b)How many elecetrons does this rep? Homework Equations...
20. ### What are the resonant wavelengths?

I don't believe we did, but if you say that it wouldn't make sense if we didn't, then why would we be assigned this question? And it says that L=5 in part b.
21. ### What are the resonant wavelengths?

We are just touching on basics of different waves, sound included. Yes we did touch a little on the nodes. No, we did not discuss tuning forks in a pipe.
22. ### What are the resonant wavelengths?

Homework Statement Consider pipe of lenght L. The pipe is closed at one end and open at the other allowing a standing wave where a node exists at the closed end and a max exists at the open end. a) what are the resonant wavelengths? b) If L=5, what is the lowest frequency? Homework...
23. ### How long should she wait?

Alright, thanks alot :D
24. ### How long should she wait?

So basically it has nothing to do with any wave equations? It`s more of a kinematics question? So light would be: 3x108=33/t t=33/3x108 t=1.1x107 So you would just add the two and it would basically be 0.1sec that the violinist should wait since t is so small for light? b) They see the...

Frequency?
26. ### How long should she wait?

Would I use the equation speed of light=(frequency)(wavelength) and then solve for frequency? Speed of light = 3x108 and wavelength = 33m?
27. ### How long should she wait?

Homework Statement An orchestra wants to have a listener in front of a conductor hear notes at the same time, played by the violinist located next to the conductor and from a drummer located 33m further back. a) How long should the violinist wait before playing her note? (assuming drummer...
28. ### Another Momentum one, sorry

Alright I got it, thanks alot :D
29. ### Another Momentum one, sorry

Would the vertical component be the same as the first equation except we would use sin60 instead of cos60?
30. ### Another Momentum one, sorry

ok i think i got it, hopefully lol: p=mv m1u1+m2u2=m1v1+m2v2cos60 (.5)(2)+(1)(0)=.5v1+(1)(.75)cos60 1=.5v1+.375 .625=.5v1 1.25=v1 b) The final direction would just be forward because the value of the speed is positive. Or do you use a formula to find the direction. I'm...