Question

Each square in the grid 0.50 m x 0.50 m in dimensions. Force F=2025 N and a Force H= 1000 N. Find the moments of each force about the points A, B, C, and D.

Answer 1

The moment about each point is the product of the lever length and perpendicular component of the force. The moment is positive if tries to rotate the lever counterclockwise and negative otherwise. For F_x=2025 N and F_y=1000 N, we have:

Relative to A:

$F_x: M=0,\\ F_y: M=0.5·5·1000=2500\text{ Nm}.$

Relative to B:

$F_x: M=0,\\ F_y: M=-0.5·1000=-500\text{ Nm}.$

Relative to C:

$F_x: M=-0.5·4·2025=-4050\text{ Nm},\\ F_y: M=-0.5·1000=-500\text{ Nm}.$

Relative to D:

$F_x: M=-0.5·5·2025=-5062.5\text{ Nm},\\ F_y: M=0.5·5·1000=2500\text{ Nm}.$