R2=2R1 v2=v1/8 V2/V1—? a2/a1—?

Based on the information provided, it seems that we are dealing with equations that could represent physical relationships, but the context or the physical quantities these variables represent isn't clear. Assuming that "R" stands for resistance, "V" for voltage, and "a" for acceleration, and considering Ohm's Law and Kinematics, we can make assumptions.

For electrical circuits and using Ohm's Law (V = IR, where V is voltage, I is current, and R is resistance), if R2 is twice R1 (R2 = 2R1), and V2 is one-eighth of V1 (V2 = V1/8), then:

V2/V1 = (V1/8)/V1 = 1/8.

Therefore, the ratio of V2 to V1 is 1 to 8.

For the accelerations (a2 and a1), we would need to understand the context in which they are used. Acceleration doesn't directly correlate with voltage or resistance like in Ohm's Law, and typically you would need additional information such as the force acting on an object or its mass (from Newton's second law, F=ma) to relate accelerations. Assuming "a" represents acceleration, the relation a2 = 2a1 would imply if a2 is twice that of a1. However, without additional context, we cannot provide a specific numerical ratio like we did for voltage.

If the "a" represents something other than acceleration, such as area, the subject matter would be different entirely. Additional context is needed to accurately determine what a2/a1 would be. Please provide more details or specify the physical context of R1, R2, V1, V2, a1, and a2 for a more precise explanation.