- #1
jasonpeng
- 19
- 0
Hey everybody. I just took a test where a problem described, "a ladder is leaning against a wall with an angle of A. It has a length L and it weighs mg. Assume no friction against the vertical wall and a frictional coefficient of B, find Ffriction"
My dad, a quantum physicist, explained how the problem was done, saying that the normal force was mg because the forces in the Y direction added up to 0, the coefficient wasn't needed, and he used Torque (clockwise) = Torque (counterclockwise) to solve for Ffriction in a systems of equations. However, first of all, it wouldn't make sense that there was extra info in the problem, and second of all, I don't understand how the Fn could be mg if it was applied to the end (it just makes logical sense that if it is applied further from the weight center, it affects the translation force less.) I think he may be out of shape in terms of classical physics and forgot the exact way to do this problem and thus I'd like somebody to explain how to ACTUALLY do the problem.
My dad, a quantum physicist, explained how the problem was done, saying that the normal force was mg because the forces in the Y direction added up to 0, the coefficient wasn't needed, and he used Torque (clockwise) = Torque (counterclockwise) to solve for Ffriction in a systems of equations. However, first of all, it wouldn't make sense that there was extra info in the problem, and second of all, I don't understand how the Fn could be mg if it was applied to the end (it just makes logical sense that if it is applied further from the weight center, it affects the translation force less.) I think he may be out of shape in terms of classical physics and forgot the exact way to do this problem and thus I'd like somebody to explain how to ACTUALLY do the problem.