An 8.1 kg watermelon is placed at one end of a 6.5 m, 234 N scaffolding supported by two cables. One supporting cable is at the opposite end of the scaffolding, and the other is 1.1 m from the watermelon. How much tension is in the cable at the end of the scaffolding? The acceleration of gravity is 9.8 m/s Answer in units of N
Here is the question and picture thanks for your help, I really need it.
http://dl.dropbox.com/u/60399655/Torque%201%202.png
Here is the question and picture thanks for your help, I really need it.
http://dl.dropbox.com/u/60399655/Torque%201%202.png
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Since you don't know the tension in the cable 1.1m from the watermelon, use this as your axis.
Clockwise moments:
(234)(2.15)
This is the weight of the scaffolding, acting in the middle of the board.Since we took the cable as the axis, instead of 3.25m as the distance, it's 2.15m, the distance from the cable to the middle of the board.
Counterclockwise moments:
(T)(5.4) + (8.1)(9.8)(1.1)
The other cable and the weight of the watermelon.
These need to be equal to each other.
(T)(5.4) + (8.1)(9.8)(1.1) = (234)(2.15)
Solving for T, and you should get 77 N
Clockwise moments:
(234)(2.15)
This is the weight of the scaffolding, acting in the middle of the board.Since we took the cable as the axis, instead of 3.25m as the distance, it's 2.15m, the distance from the cable to the middle of the board.
Counterclockwise moments:
(T)(5.4) + (8.1)(9.8)(1.1)
The other cable and the weight of the watermelon.
These need to be equal to each other.
(T)(5.4) + (8.1)(9.8)(1.1) = (234)(2.15)
Solving for T, and you should get 77 N