Finding magnitude of a particle

[sweetipie2216]

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.

 

[berkeman]

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?

 

[sweetipie2216]

my direction is north

 

[sweetipie2216]

never mind i figured out the answer. thanks for your help