What is the potential maximum speed reached by material expelled during a supernova explosion?

Answer

Roughly $30,000 ext{ km/s}$ (10% of the speed of light)

The initial explosion expels stellar material at tremendous velocities, which can approach ten percent of the speed of light, equating to approximately $30,000 ext{ km/s}$.

What is the potential maximum speed reached by material expelled during a supernova explosion?
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