The small block B rests on top of the large block A. The coefficient of static friction are shown in the figure. Determine the smallest value of the applied force P that will keep block A from sliding down the inclined plane. You MUST draw the free body diagram. -Frictionless pulley B Cord 10 kg 60 kg HB=0.3 30° HA=0.2

In the figure, block A (mass 13.2 kg) is in equilibrium, but it would slip if block B (mass 7.40 kg) were any heavier. For angle 0 = 29.6°, what is the coefficient of static friction between block A and the surface below it? Number i Units

Determine two force members first. Two blocks are each pin connected to a massless horizontal link. Determine the largest P before motion cocurs. Use 0.35 and 0.3 for the friction coefficients. 45° J c 4.5 kg 3 kg B 30°

GOAL Apply the concept of static friction to an object resting on an incline. PROBLEM Suppose a block with a mass of 2.50 kg is resting on a ramp. If the coefficient of static friction between the block and ramp is ng sin e 0.350, what maximum angle can the ramp make with the horizontal mg cos e e before the block starts to slip down? STRATEGY This is an application of Newton's second law involving an object in equilibrium. Choose tilted coordinates, as in the figure. Use the fact that the block is just about to slip when the force of static friction takes its maximum value, f. = 4n. SOLUTION Write Newton's laws for a static system (1) EF = mg sin e - u̟n = 0 in component form. The gravity force (2) EF = n - mg cos e = 0 has two components. Rearrange Equation (2) to get an n = mg cos 8 expression for the normal force n. Substitute the expression for n into EF, = mg sin 8 - H mgcos 0 = 0 → tan 8 =u. Equation (1) and solve for tan 0. Apply the inverse tangent function to get the answer.…