In the figure, a rectangular slab of slate rests on a bedrock surface inclined at angle = 28.1°. The slab has length L = 46.3 m, thickness T = 5.67 m, and width W = 12.9 m, and 1.0 cm³ of it has a mass of 3.2 g. The coefficient of static friction between slab and bedrock is 0.387. (a) Calculate the component of the gravitational force on the slab parallel to the bedrock surface. (b) Calculate the magnitude of the static frictional force on the slab. By comparing (a) and (b), you can see that the slab is in danger of sliding. This is prevented only by chance protrusions of bedrock. (c) To stabilize the slab, bolts are to be driven perpendicular to the bedrock surface (two bolts are shown). If each bolt has a cross-sectional area of 6.20 cm² and will snap under a shearing stress of 3.29 x 108 N/m², what is the minimum number of bolts needed? Assume that the bolts do not affect the normal force.

Problem 1: A 2.80kg block is placed on a rough (us=0.540) incline that makes an angle of 52.0° with respect to the horizontal. A pushing force horizontal to the ground is applied to the top of the block (This would make the force have an angle of 52.0° below the surface of the inclined plane, up the plane) to make the block stationary on the plane. What is the minimum pushing force needed to keep the block stationary on the plane? (10 points)

The distance between two telephone poles is d = 54.0 m. When a 1.20 kg bird lands on the telephone wire midway between the poles, the wire sags h = 0.206 m. (a) Draw a free-body diagram of the midpoint of the wire (where the bird is perched). mg O X* (b) How much tension (in N) does the bird produce in the wire? Ignore the weight of the wire. 3.15 Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. N Need Help? Read It

A small box of mass 4.1kg is sitting on a board of mass 1kg and length 1.1m(Figure 1). The board rests on a frictionless horizontal surface. The coefficient of static friction between the board and the box is 0.54. The coefficient of kinetic friction between the board and the box is, as usual, less than 0.54. Throughout the problem, use 9.8m/s^2 for the magnitude of the acceleration due to gravity. In the hints, use Fr for the magnitude of the friction force between the board and the box. Figure esc ! 1 FI m₂ L 2 F2 #3 1 of 1 > 80 F3 E $ 4 888 F4 Part A R Find Fmin, the constant force with the least magnitude that must be applied to the board in order to pull the board out from under the the box (which will then fall off of the opposite end of the board). View Available Hint(s) Fmin = Submit Provide Feedback % [5] ΑΣΦ 5 F5 T 1 MacBook Air 6 F6 Y & 7 www. F7 ? U N 8 00 DII FB 1 ( 9 DD F9 I ) C F10 I 1 P (1 Review I Constants F11 I + Next > F12

A sphere of mass 2.9 x 104 kg is suspended from a cord. A steady horizontal breeze pushes the sphere so that the cord makes a constant angle of 20° with the vertical. Find (a) the magnitude of that push and (b) the tension in the cord. (a) Number Units (b) Number i Units

The figure shows a container of mass m1 = 3.7 kg connected to a block of mass m2 by a cord looped around a frictionless pulley. The cord and pulley have negligible mass. When the container is released from rest, it accelerates at 0.68 m/s? across the horizontal frictionless surface. What are (a) the tension in the cord and (b) mass m2? (a) Number i Units (b) Number i Units

A chandelier hangs h = 0.74 m down from two chains of equal length. The chains are separated from one another by a length L = 0.85 m at the ceiling. The chandelier has a mass of m = 28 kg. What is the angle, θ in degrees, between one of the chains and the vertical where it contacts the chandelier?

In the figure, a rectangular slab of slate rests on a bedrock surface inclined at angle 8 = 22.8°. The slab has length L = 48.9 m, thickness T = 6.61 m, and width W = 12.7 m, and 1.0 cm³ of it has a mass of 3.2 g. The coefficient of static friction between slab and bedrock is 0.312. (a) Calculate the component of the gravitational force on the slab parallel to the bedrock surface. (b) Calculate the magnitude of the static frictional force on the slab. By comparing (a) and (b), you can see that the slab is in danger of sliding. This is prevented only by chance protrusions of bedrock. (c) To stabilize the slab, bolts are to be driven perpendicular to the bedrock surface (two bolts are shown). If each bolt has a cross-sectional area of 6.47 cm² and will snap under a shearing stress of 3.59 x 108 N/m², what is the minimum number of bolts needed? Assume that the bolts do not affect the normal force.

There are two forces on the 2.30 kg box in the overhead view of the figure but only one is shown. For F1 = 20.3 N, a = 12.1 m/s?, and e = 36.8°, find the second force (a) in unit-vector notation and as (b) a magnitude and (c) a direction. (State the direction as a negative angle measured from the +x direction.) (a) Number i+ į Units (b) Number Units (c) Number Units

In the figure below, a spider is resting after starting to spin its web. The gravitational force on the spider is 0.170 N on the junction of the three strands of silk. The junction is supported by different tension forces in the two strands above it so that the resultant force on the junction is zero. The two sloping strands are perpendicular, and we have chosen the x and y directions to be along them. The tension T, is 0.111 N. (a) Find the tension T y N (b) Find the angle the x axis makes with the horizontal. (c) Find the angle the y axis makes with the horizontal.