Question

for part (a), i will have to consider friction too, right?
and for part (b), how do i calculate the work done without knowing the distance to E.

Answer 1

For part A, yes you have to add the friction equation

Answer 2

so, is it:
2kxcos(theta)-umg

Answer 3

maybe for part b, i have to leave my answer in terms of a variable

Answer 4

Maybe.