A positively charged particle with velocity $$v$$ is moving in a magnetic field represented by dots. What is the direction of the magnetic force on the particle?

This image depicts a positively charged particle moving with velocity $$v$$ in a magnetic field. The dots represent the magnetic field lines pointing out of the plane of the image (perpendicular to the page, outwards). The velocity vector $$v$$ is shown pointing downwards.

To determine the direction of the magnetic force, we use the Lorentz force law, which states that the force $$\vec{F}$$ on a charged particle moving in a magnetic field is given by:

\[ \vec{F} = q(\vec{v} \times \vec{B}) \]

where $$q$$ is the charge of the particle, $$\vec{v}$$ is its velocity, and $$\vec{B}$$ is the magnetic field vector. Since the particle is positively charged, $$q > 0$$.

We can use the right-hand rule to find the direction of the cross product $$\vec{v} \times \vec{B}$$.

1. Point the fingers of your right hand in the direction of the velocity vector $$\vec{v}$$ (downwards).
2. Curl your fingers towards the direction of the magnetic field vector $$\vec{B}$$ (out of the page).
3. Your thumb will point in the direction of the force $$\vec{F}$$.

Following these steps, when $$\vec{v}$$ is downwards and $$\vec{B}$$ is out of the page, the resulting force $$\vec{F}$$ will be directed to the left.

Answer: The magnetic force on the particle is directed to the left.