A light horizontal bar is balanced about a pivot. Two clockwise moments are 1.2 N m and 1.8 N m. A single force produces an anticlockwise moment at a perpendicular distance of 0.50 m. What is this force?
1.5 N1.5\ \mathrm{N}1.5 N
3.0 N3.0\ \mathrm{N}3.0 N
1.2 N1.2\ \mathrm{N}1.2 N
6.0 N6.0\ \mathrm{N}6.0 N