Assignment:
A uniform plank with a length L of 6.10 m and a weight of 445 N, rests on the ground and against a frictionless roller at the top of the wall of height h = 3.05 m. The plank remains in equilibrium for any value of theta greater than or equal to 70 degress but slips if theta is less than 70 degrees. Find the coefficient of static friction between the plank and the ground.
Provide complete and step by step solution for the question, use formulas.