A positively charged particle is moving with velocity $$\vec{v}$$ between the S and N poles of a magnet. What is the direction of the magnetic force acting on the particle?

Analysis:

The image shows a positively charged particle moving with velocity $$\vec{v}$$ between the South (S) and North (N) poles of a magnet. The magnetic field lines go from North to South. Therefore, the magnetic field $$\vec{B}$$ is directed upwards, from the N pole towards the S pole.

The direction of the magnetic force on a moving charge is given by the Lorentz force formula: $$\vec{F} = q(\vec{v} \times \vec{B})$$. Since the charge is positive (q > 0), the force $$\vec{F}$$ is in the same direction as the cross product $$\vec{v} \times \vec{B}$$.

The velocity $$\vec{v}$$ is directed to the right. The magnetic field $$\vec{B}$$ is directed upwards.

Using the right-hand rule for the cross product:

1. Point the fingers of your right hand in the direction of the first vector, $$\vec{v}$$ (to the right).
2. Curl your fingers towards the direction of the second vector, $$\vec{B}$$ (upwards).
3. Your thumb will point in the direction of the resulting vector, $$\vec{v} \times \vec{B}$$.

In this case, with $$\vec{v}$$ to the right and $$\vec{B}$$ upwards, the thumb points out of the page (towards the viewer).

Conclusion:

The direction of the magnetic force acting on the positively charged particle is out of the page.

Ответ: Сила, действующая на частицу, направлена от нас (из плоскости рисунка).