Question

Problem 3. Spaghettification.] Disgruntled students have abducted a physics professor, and they have hurled them towards a black hole of mass of equal to twenty solar masses MBH = 20MSun. The prof is helplessly waving arms, and the distance between prof's feet and hands is h = 2.00 m. When prof was at distance d 1000 km from the center of the black hole the students saw something really weird. Because prof's feet are closer to the black hole than their hands, the feet are experiencing greater force than the hands and prof is being elongated to look like a strand of spaghetti. Of course, you know of the tidal force, but spaghetti – really?! (a) Calculate the difference in acceleration of prof's feet and hands (Aa = a feet - ahands) due to the gravitational attraction by the black hole. (b) Assuming that prof was initially at rest, find the distance As between hands and feet after time At = 1 s, using As = Aa* (At)?/2. Interpret your result - explain in your own words what is happening to the professor. M d h Hint: Say prof's feet or hands have mass m. The force acting on feet/hands is F = GMBHm/d®, and since acceleration of feet/hands is a = F/m, we have a = GMBH/d. In other words, you don't need to know mass of feet or hands, as their mass m cancels out. Note that distance d for feet and hands are different by dhands = d feet + h.

Answer 1