V Part A The Crab Nebula is now about 1 pc in radius. If it was observed to explode in A.D. 1054, roughly how fast is it expanding? (Assume a constant expansion rate.) Express your answer using one significant figure. v = 1000 km/s Submit Previous Answers Correct Part B Is that a reasonable assumption? Essay answers are limited to about 500 words (3800 characters maximum, including spaces). 3800 Character(s) remaining Submit Request AnswerPart A v Using the Sun's current luminosity, estimate its total energy output, assuming a 10 year main-sequence lifetime. Express your answer to one significant figure and include the appropriate units. Etotal = 1x1044 J Submit Previous Answers Correct Part B How does this compare with the energy released by a typical supernova? Essay answers are limited to about 500 words (3800 characters maximum, including spaces). 3800 Character(s) remaining Submit Request