Suppose that in Fig. 4-5(c) the block is at rest. The angle of the incline is slowly increased. At an angle θ = 42°, the block begins to slide. What is the coefficient of static friction between the block and the incline? (The block and surface are not the same as in Problems 4.5 and 4.6.)

Problem 4.5

Each of the objects in Fig. 4-5 is in equilibrium. Find the normal force F_N in each case.

Problem 4.6

For the situations of Problem 4.5, find the coefficient of kinetic friction if the object is moving with constant speed. Round off your answers to two significant figures.

Transcribed Image Text:

F = 500 N (a) 200 N 30.0⁰ 200 N 30.0⁰ F-150 N FN Fig. 4-5 Fw=200 N (c)