A block experiences three forces acting on it: Force 1 of 10N south, Force 2of 10N East, Force 3 of 5N North. The block moves 2 meters west. Which did most work?

Answer 1

work done is force times distance IN THE DIRECTION OF the force.
It moved West
force1 did nothing
force 3 did nothing
Force 2 was EAST but the block moved WEST so it did NEGATIVE work on the block (slowed it down) -10 N * 2 m = -20 Nm = -20 Joules

Answer 2

Fr = -10i + 10 + 5i = 10 - 5i
= 11.2N.[-26.6o] = 11.2N.[333o] CCW = 63o E.of S. = Resultant force.

Based on the resultant force, it is not possible for the block to move west.
Do you mean 2 meters East?

Answer 3

It was already moving :)