Alow spin fe3 complex ion obeys the aufbau principle, placing all of the electrons in the lowest energy orbitals (t2g). fill in the orbital to the right for the low spin case.

Ke reqd to move from 0 to 50 will be proportional to 50x50 or 2500. this is equal to w.  to change vel from 50 to 150 you need energy prop to 22500 - 2500 = 20,000. this corresponds to 8w.  best answer is a) . work reqd is prop to velocity squared. 

Despite their crazy structure, human bones are surprisingly good!