What Is the Angle of the Rod in the Magnetic Field?

Dart82
Messages
56
Reaction score
0
1. Homework Statement
a thin, uniform rod, which has a length of 0.45 m and a mass of 0.080 kg. This rod lies in the plane of the paper and is attached to the floor by a hinge at point P. A uniform magnetic field of 0.25 T is directed perpendicularly into the plane of the paper. There is a current I = 3.8 A in the rod, which does not rotate clockwise or counter-clockwise. Find the angle .
21_35.gif




2. Homework Equations
F = ILB sin(theta)
F= ma


3. The Attempt at a Solution
heres what i was thinking:
if F = ILB sin(theta) then let ma = ILBsin(theta)

so solve for theta:
arcsine(ILB/ma) = 33.0 degrees however, i was told this is wrong.
 
Physics news on Phys.org
Do the magnetic and gravitational forces act in the same direction? Hint: no. Draw a force diagram.
 
Also, is the theta in your picture the same as the theta in the B equation? Hint: no.
 
thanks for the help. i think it got it finally.
 
Hi, I had an exam and I completely messed up a problem. Especially one part which was necessary for the rest of the problem. Basically, I have a wormhole metric: $$(ds)^2 = -(dt)^2 + (dr)^2 + (r^2 + b^2)( (d\theta)^2 + sin^2 \theta (d\phi)^2 )$$ Where ##b=1## with an orbit only in the equatorial plane. We also know from the question that the orbit must satisfy this relationship: $$\varepsilon = \frac{1}{2} (\frac{dr}{d\tau})^2 + V_{eff}(r)$$ Ultimately, I was tasked to find the initial...
The value of H equals ## 10^{3}## in natural units, According to : https://en.wikipedia.org/wiki/Natural_units, ## t \sim 10^{-21} sec = 10^{21} Hz ##, and since ## \text{GeV} \sim 10^{24} \text{Hz } ##, ## GeV \sim 10^{24} \times 10^{-21} = 10^3 ## in natural units. So is this conversion correct? Also in the above formula, can I convert H to that natural units , since it’s a constant, while keeping k in Hz ?
Back
Top