Question

wo builders carry a sheet of drywall up a ramp.

Assume that W = 1.70 m, L = 3.30 m, θ = 21.0°, and that the lead builder carries a (vertical) weight of 131.0 N (29.5 lb). What is the (vertical) weight carried by the builder at the rear?

The builder at the rear gets tired and suggest that the drywall should be held by its narrow side.

What is the weight (in N) he must now carry?

Answer 1

Given data The vertical force is F 131 N Assume that W = 1.70 m, L = 3.30 m, θ = 21.0° dAC F. dAB 2 2 FcL cos Lcos θ--W sin θ 2 2 131x3.3cos(21) 0.5x 3.3cos (21)-0.5x1.7sin (21 403.58 1.54-0.3 325.47 N The sum of the forces in the y direction is zero A B C 325.47-131 194.47 N

dAC-W cos θ dAB _ _ cos@--sin θ 2 2 2 2 W cos a 7csl(21)-3 sia(21)2547 1.7 cos(21) 3.3 sin (21) sın 64.67 1.59 40.67 N The sum of the forces in the y direction is zero A B C 325.47-40.67 284.8 N