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hskrnt8590
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Homework Statement
A nonuniform fire escape ladder is 6.0 long when extended to the icy alley below. It is held at the top by a frictionless pivot, and there is negligible frictional force from the icy surface at the bottom. The ladder weighs 250 , and its center of gravity is 2.0 along the ladder from its bottom. A mother and child of total weight 750 are on the ladder 1.5 from the pivot. The ladder makes an angle theta with the horizontal.
1)Find the magnitude of the force exerted by the icy alley on the ladder?
2)What is the direction of the force exerted by the icy alley on the ladder? (Up/down)
3)Find the magnitude of the force exerted by the ladder on the pivot.
4)Do your answers in parts A and C depend on the angle theta? (Yes/No)
Homework Equations
F=ma
Torque= RxL
The Attempt at a Solution
1) Isn't the magnitude of the force by the icy alley on the ladder just the normal force? Since it doesn't mention the ladder sliding it has to be stationary which means all forces are cancelling out. 250+750 = 1000 Newtons upward.
2) It should be upward to cancel out the weight of the people and ladder
3) It would be the normal force of the wall on the ladder correct? This would be 0 though since friction is negligible I think.
4) The forces shouldn't depend on theta because they are strictly talking forces and not torque.
These are my initial tries, but the first one is wrong when I try the answer, so I am assuming my thinking is flawed. Any help would be appreciated.