Equilibrium: Rotational Motion

Question

A 2150 kg drawbridge, 8.74 m long, is held up by a chain attached to the end. The chain makes a 51.0 degree angle. What force does the chain exert?

(Don't forget: w=mg, at the center of the object.)

(Unit = N)

Answer 1

mgl/2 = Tlsinθ; T = mg/(2sinθ) = 2150kg·9.81m/s²/(2sin51°) = 13570 N

Answer 2

a) assume the 51 degree angle is measured CW from the bridge

b) T = 2150*9.81/2/sin(51)= 13570 Newtons