Final answer:
The speed of each particle in a circle under the mutual gravitational attraction can be determined using the formula for orbital speed.
Step-by-step explanation:
The speed of each particle moving in a circle under the mutual gravitational attraction can be determined using the formula for orbital speed. The orbital speed of a particle is given by the equation:
v = √(GM/r)
Where v is the orbital speed, G is the gravitational constant, M is the total mass of the system, and r is the radius of the circle. In this case, since the particles have the same mass and are moving in the same circle, the formula simplifies to:
v = √(GM/2r)
Therefore, the speed of each particle is determined by the total mass of the system and the radius of the circle.