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PFStudent
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Homework Statement
21. An electron follows a helical path in a uniform magnetic field of magnitude [itex]0.300{\textcolor[rgb]{1.00,1.00,1.00}{.}}T[/itex]. The pitch of the path is [itex]6.00{\textcolor[rgb]{1.00,1.00,1.00}{.}}{\mu}m[/itex], and the magnitude of the magnetic force on the electron is [itex]{2.00{\times}{{10}^{-15}}}{\textcolor[rgb]{1.00,1.00,1.00}{.}}N[/itex]. What is the electron's speed?
Homework Equations
[tex]
{\vec{F}_{E}} = {q{\vec{E}}}
[/tex]
[tex]
{\Delta{V}_{p}} = {{-}{\int_{r_{0}}^{r_{1}}}{\vec{E}_{p1}(r)}{\cdot}{d{\vec{r}}}}
[/tex]
[tex]
{\vec{E}} = {{-}{\nabla}{V(r)}}
[/tex]
[tex]
{\vec{E}} = {{-}{\frac{\partial}{\partial{r}}}{\left[{V(r)}\right]}{\hat{r}}}
[/tex]
[tex]
{\vec{F}_{B}} = {q{\vec{v}}{\times}{\vec{B}}}
[/tex]
The Attempt at a Solution
This problem isn't so hard to solve, as intrepreting the information the problem is giving.
Like, when the problem says,
PFStudent said:The pitch of the path is [itex]6.00{\textcolor[rgb]{1.00,1.00,1.00}{.}}{\mu}m[/itex],
What exactly do they mean by "pitch of the path," and why are they giving it as a measure of distance (ie. [itex]{m}[/itex])?
In addition, they mention that the electron, "follows a helical path," by helical path--they're basically saying an upward spiral path, is that correct?
Also, since a helical path has some curvature to it, does the centripetal force apply to this problem? (even though a helical path is not the same as going around in a cricle)
And if the centripetal force does apply, why?
Any help is appreciated.
Thanks,
-PFStudent
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