Answer and Explanation:
To compute the magnitude of the moment M0 of the 260-lb force about the axis O−O, we can use the formula for the moment of a force about an axis:
M0 = F * d * sin(θ)
where F is the magnitude of the force, d is the perpendicular distance from the axis to the line of action of the force, and θ is the angle between the force vector and a line drawn from the point where the force is applied to the axis.
In this case, F = 260 lb, d = 13 in., and θ = 29°. Plugging these values into the formula above, we get:
M0 = 260 lb * 13 in. * sin(29°)
M0 ≈ 1853.6 in-lb
So, the magnitude of the moment M0 of the 260-lb force about the axis O−O is approximately 1853.6 in-lb.