A uniform board is leaning against a smooth vertical wall. The board is at an angle θ above the horizontal ground. The coefficient of static friction between the ground and the lower end of the board is 0.650. Find the smallest value for the angle θ, such that the lower end of the board does not slide along the ground.

One end of a uniform meter stick is placed against a vertical wall. The other end is held by a lightweight cord that makes an angle 0 with the stick. The coefficient of static friction between the end of the meter stick and the wall is H, = 0.400. A. (2 points) What is the maximum value that 0 can have if the stick is to remain in equilibrium? Express your answer in degrees. B. (4 points) A block of the same weight as the meter stick is suspended from the stick at a distance x from the wall, as shown below. Assume that 0 =15.0° in this part of the problem. What is the minimum value of x for which the stick will remain in equilibrium? Answer: x > C. (4 points) When 0 =15.0°, how large must the coefficient of static friction be so that the block can be attached 0.100 [m] from the left end of the stick without causing it to slip? Answer: Hs 2

A uniform ladder 5.0 m long rests against a frictionless, vertical wall with its lower end 3.0 m from the wall. The ladder weighs 160 N. The coefficient of static friction between the foot of the ladder and the ground is 0.40. A man weighing 740 N climbs slowly up the ladder. (a) What is the maximum friction force, in Newtons, that the ground can exert on the ladder at its lower end? (b) What is the actual friction force, in Newtons, when the man has climbed 1.0 m along the ladder? (c) How far, in meters, along the ladder can the man climb before the ladder starts to slip?

One end of a uniform € = 3.40-m-long rod of weight w is supported by a cable at an angle of 8 = 37° with the rod. The other end rests against a wall, where it is held by friction (see figure). The coefficient of static friction between the wall and the rod is μ = 0.590. Determine the minimum distance x from point A at which an additional weight w (the same as the weight of the rod) can be hung without causing the rod to slip at point A. B