Statics: Equilibrium and circular lawn roller

AI Thread Summary
To determine the horizontal force required to pull a 100 kg circular lawn roller over a 3 cm step, the roller's radius of 30 cm and its pivot point at the edge of the step must be considered. The problem involves analyzing forces in both the X and Y directions, applying the equations for static equilibrium where the sum of forces and moments equals zero. The professor suggests that as the roller ascends, the normal force transitions from the ground to the step, complicating the calculations. Two unknowns arise from the forces acting on the roller, necessitating the use of torque considerations about the edge of the step for a complete solution. Understanding these dynamics is crucial for accurately calculating the required force.
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1. What horizontal force F will pull the 100 kg lawn roller over the step? What is the value of F if it is directed normal to AC?

I can't draw a picture for you, but i can describe it. There is a circular lawn roller in contact with a step that is 3cm in height. The roller is currently resting on the ground. the radius of the roller is 30 cm. I initially need to find a force in the horizontal direction, then find a force that is 45 degrees up from that. You can mark the top of the step as point A and the center of the roller as point C. Both forces start from C.

Homework Equations



sum F = 0
sum M = 0

The Attempt at a Solution



I tried solving for the force in both the X and Y directions. My professor gave me the hint that as the roller is goin up the step, the normal force will end up disappearing from the ground to the step. This however, still has me confused. He told me that i will have 2 unknowns and 2 equations. I have the equations, but I am uncertain of what I am doing to get the force.
 
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Hint: As the roller climbs the step it must rotate about the edge of the step. Consider torques about that point.
 
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