Final answer:
Rotary saw blades can potentially spin at speeds greater than 10,000 rpm, which is supported by examples of other equipment like grindstones that reach 6500 rev/min and helicopter blades which rotate rapidly.
Step-by-step explanation:
The rotary saw blades can spin at tremendously high speeds. From the information given, a workshop grindstone with a smaller radius of 7.50 cm can rotate at 6500 rev/min, and helicopter blades, which endure large centrifugal forces, also rotate rapidly. If we extrapolate from these examples and recognize that rotary saws are designed to cut through materials efficiently, it’s reasonable to suggest that their blades could spin at very high speeds as well. Considering the options given, it is not unreasonable for a rotary saw blade to reach speeds of more than 10,000 rpm, making answer D the most likely choice.
In terms of practical understanding, option D suggests a high-end capability which may be possible in specialized or industrial equipment. It should be noted that most standard saws will have lower rpm specifications for safety and equipment longevity.