Confusion on applying right hand rule

AI Thread Summary
The discussion centers on confusion regarding the application of the right-hand rule in a physics problem involving a proton moving through a magnetic field. The magnetic field is vertical, while the proton moves horizontally, leading to discrepancies in the calculated magnetic deflecting force. The participant calculates the force as pointing in the z direction, contrary to the book's indication of it being horizontal to the east. Clarification is sought on how to properly relate geographic directions (north/south, east/west, up/down) to the Cartesian coordinate system (x, y, z). The conversation emphasizes the importance of ensuring that the force is always perpendicular to both the magnetic field and the velocity vector.
Genericcoder
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Hi guys I always get confused when I do the right hand rule like here when I apply it to this problem I am getting different answer than what the book have.

A uniform magnetic field B, with magnitude 1.2 mT, points vertically upward throughout the volume of the room in which you are sitting. A proton with kinetic energy of 5.3 MeV moves horizontally to the north through a certain point in the room. What magnetic deflecting force acts on the proton as it passes through this point ? The proton mass is 1.67 * 10^-27 kg.

so Fb = 6.1 * 10^-15 N; the book then says the force is sideways in horzontally to the east. I am getting it pointing in the z direction even when using cross product

FB = q<v,0,0> x <0,B,0>

Fb = qvB k^ direction
 
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What's your convention for relating north/south, east/west, and up/down to the x, y, and z axes? You know you've mixed something up if the force isn't perpendicular to the B field and the velocity.

(I'm assuming that you are using i,, j, and k as unit vectors in the x, y, and z directions respectively).
 
Ye I am using i j k as unit vectros x,y,and z directions respectively.. but I think that's what I have not relating north/south up down to x and y and z directions..
 
Shouldn't your field be (0,0,B)?
 
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