A mass is tied to a string. The mass is traveling in a circular path. At the bottom of the circular path, what is the max speed of object before the string will break? the r= 54m, mass =2.5kg. The tinsel strength of the string is 132N. I also need the work.

The answer is a.  i hope this

I'm pretty sure the answer is c 

Year  1936,  lehman predicted that the earths 'inner core' is solid. she observed that the seismic signals during her study were bent and did not pass through instead bouncing back. later it was confirmed that the earth's inner core was solid made up of nickel-iron and had a molten outer core.

Dshould be the right answer i think