#1

in a simple model of the hydrogen atom, the election revolves in a circular orbit around the proton with a speed of 1.1 x 10^6 m/s. determine the radius of the elctron's orbit. [hint; see circular motion]

the question is in the unit about electric charge and field, so i need some way to link some equation from that chapter to a circular motion equation. i really have no idea though, nor would i care if this weren't a graded assignment. any idea?

the question is in the unit about electric charge and field, so i need some way to link some equation from that chapter to a circular motion equation. i really have no idea though, nor would i care if this weren't a graded assignment. any idea?

#2

Not a clue, I'm doing chemistry this year... I looked online, but didn't find a good formula... I found one for astrology if you ever need it... but aside from that, I'll keep looking, but nothing yet.

#3

F = ma

because this is circular motion you use this

a = v^2/r

That means:

F = (mv^2)/r

To solve for r you would change this equation to

r = (mv^2) / F

You should have the mass and speed provided by the question. Now you need to solve F

Use whatever equation you want from electric charge unit to get F.

Any questions?

because this is circular motion you use this

a = v^2/r

That means:

F = (mv^2)/r

To solve for r you would change this equation to

r = (mv^2) / F

You should have the mass and speed provided by the question. Now you need to solve F

Use whatever equation you want from electric charge unit to get F.

Any questions?

#4

sorry for double post but are you using coulomb's law to get force?

#5

Alright, I'll stop looking now... lol

#6

^^x3That sounds right, and you can use F=(kq1q2/)r^2 (k=Columb's constant, q1= charge of proton, q2 = charge of electron. Use centripetal accel like Mr. Pink showed you to help find the radius.

#7

F = ma

because this is circular motion you use this

a = v^2/r

That means:

F = (mv^2)/r

To solve for r you would change this equation to

r = (mv^2) / F

You should have the mass and speed provided by the question. Now you need to solve F

Use whatever equation you want from electric charge unit to get F.

Any questions?

yea, mass wasn't provided in the equation, what m should i be using, mass of a hydrogen atom i assume? i havn't done chem in 2 years btw and have no memory of how to get the mass of a hydrogen atom btw

#8

yea if you're using F=(kq1q2/)r^2

you can derive the whole thing to

kq1q2/mv^2 = r

you can derive the whole thing to

kq1q2/mv^2 = r

#9

The mass would be a proton and electron's mass combined I believe. In my physics class on the reference table we get the mass and charge of a proton & electron.

#10

sorry for double post but are you using coulomb's law to get force?

to be honest i'm not even sure anymore. i've been working on this and 13 other problems for like 3 hours and i'm just totally gone at this point.

#11

use mass of electron because that's the one that is moving. Your physics book will give you your e mass

#12

^^Oh yeah, that's true. Do that.

#13

The mass would be a proton and electron's mass combined I believe. In my physics class on the reference table we get the mass and charge of a proton & electron.

thanks

#14

it's not proton and electron combined, it's just electron because the electron is the one moving. The proton is stationary

#15

Just do the mass of the electron because that's what the force is on that you're calculating, I was wrong, Pink's right

#16

thanks all. i'm not sure if i've got it but this is farther than i've got on my own.

#17

send me an e-mail if you want, I really like physics