Calculating Magnetic Force and Acceleration of a Proton

[brunie]

A proton travels with a speed of 3.00 x 10^6 m/s at an angle of 44.0° with the direction of a magnetic field of 0.730 T in the +y direction.

(a) What are the magnitude of the magnetic force on the proton?
(b) What is its acceleration?

Ok for magnitude of force,

I used F = qvB sinø
= (1.6E-19)(3E6)(.73)sin44
= 2.437 E-13

But I was unable to find an equation for aceleration in a magnetic field in my notes, can anyone help me out?

Thanks

 

[robb_]

What does the path of the motion look like?

 

[brunie]

lol i have no idea,
but could this be solved just by using Fnet = ma
where Fnet incorporates the magentic force and gravitational force?

 

[robb_]

I doubt you need to include gravitational effects here.
The path of the motion is a hint as to how to find the solution. Any guesses?

 

[brunie]

well i kno initially its moving at the angle of 44˚, but the magnetic field should affect it to move in the positive y direction i think

 

[robb_]

Oh, you need to revisit the right hand rule to determine the direction of the force. This is an important effect for these types of problems.

 

[brunie]

but wouldn't using the RHR in this case introduce the 3rd dimension, because it would be coming out ?

 

[brunie]

?

 

[robb_]

yes, from the cross product.

 

[brunie]

so if we know it is coming out, how does it help solve for acceleration?

 

[robb_]

So at that point the force is out, does it remain in that direction?

 

[brunie]

i assume so

 

[robb_]

If the object has a net force acting on it, it will accelerate in that direction. So the velocity changes; remember that the direction of the force is dependent on the direction of the velocity vector, which changes.

 

[brunie]

so is there a way/formula to solve for acceleration by knowing this?

 

[robb_]

Sorry, if you are looking for me to give you a formula to plug numbers into, I can't help you.
If you understand the motion in your mind's eye, you will recognize the solution (hopefully).

 

[brunie]

fyi, i was right,
the equation has to do with fnet = ma
where fnet incorporates magnetic force

so next time if u don't kno wut ur talking about please don't answer a question for sum1... instead of saying ok wut u said might make sense u overcomplicate everything

 

[robb_]

My apologies, I was for some reason thinking we were looking for the radius of motion.
My bad
In my opinion, I do not think that the questions I prompted were useless. I still think you should try to understand the motion of the charged object through the B field.