# Physics questions about magnetic fields and particles?

What speed must an alpha particle maintain if it is to remain suspended, relative to Earth’s surface, as it travels on a tangent to Earth’s surface and perpendicularly through Earth’s magnetic field of 50.0uT?

I could use some help with this. I have been staring at it and can't figure out where to go.Any help is appreciated, thanks.

### 2 Answers

- ☼¿☼Lv 59 years agoBest Answer
In order for the particle to be suspended, the magnetic force supporting it must balance the force of gravity pulling down.

Fnet=Fg-Fb=0N

Fg-Fb=0

Fg=Fb

mg=qvB(sin x)

since x is the angle compared to the magnetic field, and the question states this to be perpendicular, the angle (x) is 90. sin90=1, therefore we can get rid of it to make our algebra easier.

mg=qvB

v=mg/qB

where m is the particle's mass, g is the acceleration of gravity near the earth's surface, q is the particle's charge, and B is the strength of the magnetic field.

mass is the mass of two protons (an alpha particle is a helium nucleus, which consists of two protons).

m=2(1.673e-27) kg

g=9.8N/kg

the charge is the total charge of two protons

q=2(1.6e-19) C

B is the magnetic field, in this case, of the earth. This must be in Tesla.

B=50.0uT=50.0e-6 T

v=(9.8)*(1.673e-27)*(2)/(2)*(1.6e-19)*(50.0e-6)

=2.049425e-3 m/s

cheers.

- dipalmaLv 43 years ago
a million. NO NO NO!! : ). do no longer think of of electric skill power because of the fact the comparable as electric skill. in spite of the shown fact that, they are appropriate in that P.E.=EPE/q. 2. the dimensions of the circle relies upon on how lots cost is interior and around the circle. tension and momentum of a charged field are appropriate in that the stress because of centripedal acceleration could be equivalent to the momentum given off interior the tangential direction whilst floating around an orbit as a manner to no longer bypass out or into the midsection. the better the cost of a particle, the greater advantageous the ring. in case you realize approximately photons and easy-weight, those artwork on the comparable concept in that once an electron is in a more advantageous power state, the way that an electron strikes all the way down to decrease power states is by ability of freeing power interior the kind of a photon. subsequently, you could think of of this as your 'length' of the particle. whilst at bigger power states, the electron is farther removed from the midsection because of all of the flexibility that replace into as quickly as saved in it. Then as quickly because it releases its power, the state of the electron lowers and a photon is released. So, greater power, bigger circle. wish that facilitates!