# Magnetic Forces on Charged Particles

#### einsteinoid

1. Homework Statement

A particle with a charge of +8.4 µC and a speed of 55 m/s enters a uniform magnetic field whose magnitude is 0.30 T. For each of the cases in the drawing, find the magnitude and direction of the magnetic force on the particle. 2. Homework Equations

B = F / [q(VsinΘ)]

3. The Attempt at a Solution

Ok, for case (a) I tried the following:

- 30 = F / [8.4*10^6(55sin30)]
- 30 = F / 27.5
- 30 * 27.5 = F
- F= 825 N

Where am I going wrong? Thanks!

Related Introductory Physics Homework Help News on Phys.org

#### LowlyPion

Homework Helper
Welcome to PF.

Remember these are vectors and the Force vector will be in what direction?

And it is determined by what scalar operation?

#### LowlyPion

Homework Helper
Also note your B field is .3T

#### einsteinoid

Ah, of course. I'm not sure how I kept reading B as "30" rather than ".3" lol.

So the actual answer would be 6.93E-5.

Thanks!

### Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving