Sir Lost-a-Lot dons his armor and sets out from the castle on his trusty steed i
ID: 1409833 • Letter: S
Question
Sir Lost-a-Lot dons his armor and sets out from the castle on his trusty steed in his quest to improve communication between damsels and dragons. Unfortunately his squire lowered the draw bridge too far and finally stopped it 20.0° below the horizontal. Lost-a-Lot and his horse stop when their combined center of mass is 1.00 m from the end of the bridge. The uniform bridge is 8.00 m long and has a mass of 2100 kg. The lift cable is attached to the bridge 5.00 m from the hinge at the castle end, and to a point on the castle wall 12.0 m above the bridge. Lost-a-Lot's mass combined with his armor and steed is 850 kg. Hint: First determine all the angles and lengths of the triangle made by the wall, the cable, and the drawbridge. (a) Determine the tension in the cable. (b) Determine the horizontal force component acting on the bridge at the hinge. magnitude direction to the right to the left (c) Determine the vertical force component acting on the bridge at the hinge. magnitude direction downwards upwards Comment
Explanation / Answer
Here, top angle = 18.92 degree
left angle = 109.96 degree
right angle = 51.12 degree
a) Here, T * 5 * sin51.12 = 2100 * 9.8 * 4 + 850 * 9.8 * 7
=> T = 36130.2 N
=> Tension in cable = 36130.2 N
b) Here, Fh * 12 = (2100 * 9.8 * 4 + 850 * 9.8 * 7)/cos20
=> Fh = 12471.27 N
=> Horizontal force component = 12471.27 N
=> Direction = to the right
c) Vertical force component = (2100 * 9.8 * 4 + 850 * 9.8 * 7)/(12 * cos20)
= 34264.55 N
=> Direction = downwards