Find the work that needs to be done so that a homogeneous rod lying on the floor, the mass of which is 4 kg

Find the work that needs to be done so that a homogeneous rod lying on the floor, the mass of which is 4 kg and the length of 3 m, is positioned at an angle of 30 ° to the horizontal.

Given: m = 4kg g = 10m / s ^ 2 L = 3m Sin = 30 ° = 0.5
Decision :
A = FSsin; F = mg; S = 1 / 2L; => A = mg * 1 / 2L * sin = 4 * 10 * 0.5 * 3 * 0.5 = 30 (J)
Answer: A = 30 J