Answers (cont.)
n2.) Since position #2 is half way down total energy will be half in PE and half in KE
nSo…KE at position #2 will be half that at position #3
nSo…KE at position #2 is 78.125J
nThen use KE (at #2)=78.125J =1/2 x 0.5kg x v2
nv=17.68m/s at position #2