Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

A student is standing on a ladder as shown in the figure to the right. Each leg

ID: 1460707 • Letter: A

Question

A student is standing on a ladder as shown in the figure to the right. Each leg of the ladder is 2.4 m long and is hidged at point C. The tie-rod (BD) attached halfway up and is 0.74 m long. The student is standing at a spot 1.8 m along the leg and her weight is 463 N. (You may ignore the weight of the ladder and any minor friction between the floor and the legs.)

1)What is the tension in the tie-rod?

2)What is the vertical component of the force of the ground on the ladder leg at point A?

3)What is the horizontal component of the force of the ground on the ladder leg at point A?

4)What is the vertical component of the force of the ground on the ladder leg at point E?

Explanation / Answer


L = 2.4

l = 1.8

sintheta = (x/2)/(L-l) = (0.74/2)/(2.4-1.8))

theta= 38


along vertical

N + N - w = 0

N = w/2 = 463/2 = 231.5


net torque about c = 0

N*L*sin38 = W*(L-l)*sin38 + T*L/2*cos38

231.5*2.4*sin38 = 463*(2.4-1.8)*sin38 + T*1.2*cos38


T = 180.8 N

(2)

Fv = W/2 = 231.5 N

(3)

Fh = -T = -180.8 N


(4)


Fv = N = 231.5 N