Finding magnitude of a particle

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The discussion focuses on calculating the magnetic force on a dust particle with a charge of -1.0 x 10^-18 C, moving in a 0.90 T magnetic field. The participant initially calculated the force using the formula f = qvb but arrived at an incorrect answer. After seeking help, they realized their mistake in determining the direction using the right-hand rule, initially stating it was north. Ultimately, they corrected their understanding and found the correct answer.
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Homework Statement


A magnet produces a 0.90 T field between its poles, directed to the east. A dust particle with charge q = -1.0 10-18 C is moving straight down at 0.70 cm/s in this field. What is the magnitude and direction of the magnetic force on the dust particle?


Homework Equations



f=qvb

The Attempt at a Solution


(1.0e-18)(.007)(.90)=-6.3e-21 which is wrong

I followed the same format as someone else and my answer is wrong. can you help point out what the mistake is? thanks.
 
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sweetipie2216 said:

Homework Statement


A magnet produces a 0.90 T field between its poles, directed to the east. A dust particle with charge q = -1.0 10-18 C is moving straight down at 0.70 cm/s in this field. What is the magnitude and direction of the magnetic force on the dust particle?


Homework Equations



f=qvb

The Attempt at a Solution


(1.0e-18)(.007)(.90)=-6.3e-21 which is wrong

I followed the same format as someone else and my answer is wrong. can you help point out what the mistake is? thanks.



Your magnitude looks correct. What direction did you get via the right-hand rule?
 
my direction is north
 
never mind i figured out the answer. thanks for your help
 
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