There is a good way to determine the direction of the force. We know that the velocity, the magnetic field, and the force are all perpendicular to each other, just like the axes are in an x, y, z coordinate system. You can use your right hand to find the direction of the force. Place your hand as shown, and only use your thumb, forefinger and the middle finger. They should be held at right angles to each other. The thumb represents the force. The forefinger represents the direction of the velocity. And, the middle finger represents the magnetic field. This is known as the right hand rule and it is very helpful in figuring out the direction of the force. Be careful, though - if you use your left hand this won't work! Let's go back to our formula F equals the cross product of qv and B. If q is positive, F points in the direction of v cross B. The Right Hand Rule that we just discussed applies. If q is negative, F points in the direction opposite that of v cross B. So a positive charge results in F pointing up, and a negative charge results in F down. Use the right hand rule to determine the direction of the force that will act on this charged particle. Will the force point

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