Clock #1 is positioned so that 12 o\'clock points to the top of the page. Clock

Question

Clock #1 is positioned so that 12 o'clock points to the top of the page. Clock #2 is lined up and rotated so that the straight line from the center of clock #1 to the center of clock #2 passes through "2" o'clock mark on clock #1 and then through the "4" o'clock mark on clock #2.
Each clock has a positive charge at its center. The clock #1's charge has a velocity directed toward its "4" o'clock mark; clock #2's charge is moving toward its "7" o'clock mark.
What is the direction of the magnetic force exerted on the charge located at the center of clock #1, due to the other charge?

Explanation / Answer

The magnetic field is a positive multiple of q(VxR) where "q" is the charge, "V" is the velocity vector of the charge, "R" is the position vector relative to the charge, and "x" is the vector cross-product, perpendicular to both V and R and forming a "right-handed" coordinate system. So, at the center of Clock#1 (up from Clock#2, where the electron is moving to the left), VxR points perdicular to the page downward. But "q" is negative, so the magnetic field, B, is pependicular to the page pointing up.

The force on a moving charge due to a magnetic field is also given by a cross-product: F=q(VxB), where "F: is the force vector, "q" is the charge, "V" is the velocity vector of the charge, "B" is the magnetic field vector, and "x" is the vector cross product. So the direction of the force, perpendicular to B, is within the plane of the page. The force is also perpendicular to V. Keeping in mind that "q" is negative, is the force directed toward 11 o'clock or 5 o'clock?

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