Chapter 4, Problem 148P

A 1200 N-m couple moment is applied at B in the direction shown. Find the support reactions at O.

Replace the three forces acting on the rectangular solid with a wrench. Specify the magnitude of the moment Massociated with the wrench. Enter a positive number for M if the wrench acts in a positive sense, enter a negative number if it acts in the negative sense. Specify the (x,y,z) coordinates of the point P in plane ABCD through which the line of action of the wrench passes. Illustrate the wrench moment and resultant in an appropriate sketch. 25 N 95 mm. Answers: M= y= 55 mm, 29 40 mm 20 N 110 mm. B N-m mm mm mm 35 mm 30 N

Replace the two forces acting on the pole by a wrench. Write the force R and moment M associated with the wrench as vectors and specify the coordinates of the point P in the y-z plane through which the line of action of the wrench passes. Assume F₁ = 46 N, F₂ = 107 N, a = 1.6 m, b = 6.3 m. F₁ Answers: R=( i M = (i I Force and moment associated with wrench Coordinates of point P. (y,z) = (i F₂ T b i+ i ¡+ i i j+ i j+ ) m i k) N k) N-m