Calculating Force P Needed to Lift 150kg Cylinder

AI Thread Summary
To determine the smallest force P needed to lift a 150kg cylinder, the coefficients of static friction at points A, B, and C are 0.7, 0.3, and 0.4, respectively. The user describes the forces acting on the cylinder and wedge, including normal and frictional forces at each point. They express difficulty in visualizing the problem due to scanner issues but provide equations for normal and frictional forces based on the cylinder's weight and angles involved. The calculations include normal forces at points A and B, as well as frictional forces at those points. The discussion focuses on resolving the forces to find the necessary lifting force P.
Lancelot59
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I've tried a whole manner of different things to try and solve this:

Prob.8-67.jpg


Determine the smallest force P needed to lift this 150kg cylinder.
Coefficients of static friction
At A: 0.7
At B: 0.3
At C: 0.4

I've tried different things and I'm lost on how to solve it.
 
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Lancelot59 said:
I've tried a whole manner of different things to try and solve this:

Prob.8-67.jpg


Determine the smallest force P needed to lift this 150kg cylinder.
Coefficients of static friction
At A: 0.7
At B: 0.3
At C: 0.4

I've tried different things and I'm lost on how to solve it.

Could you please show us your two FBDs and what equations you have written so far?
 
berkeman said:
Could you please show us your two FBDs and what equations you have written so far?

My scanner is giving me issues. It doesn't get along with Linux. I'll just describe them.

The drum has a normal and force of friction at point A At point B there is a normal that is at 80 degrees from the x axis, and different frictional force. It also has a weight force.

The wedge has the pushing force and the force of friction with respect to the ground on it. There is a force of friction at point B opposite to the direction on the drum, and a normal perpendicular to the top face. The problem didn't specify a mass for the wedge, so I decided to neglect it.

Normal Force At B:
FNB=150*9.8*sin(10)+Fp*sin(10)

Frictional Force At B:
FFB=0.3FNB

Normal Force At A:
I reasoned that the only thing pushing the cylinder into the wall would be it's own weight force pulling it down the wedge, and the horizontal component of the frictional force at point B

FNA= 150*9.8*sin(10)+FFBcos(10)

Frictional Force At A:
FFA=0.7FNA

Normal Force At C:
I think the only source would be the direct weight of the cylinder
FNC=150*9.8

Friction Between Wedge and Ground:
FFC=150*9.8*0.3
 
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