A mass of weight w sits on a level surface. One end of the surface is raised until the block begins to slide down the ramp at a constant velocity. What is the coefficient of friction between the block and the incline plane?

A loaded penguin sled weighing 72.0 N rests on a plane inclined at angle 0 = 22.0° to the horizontal (see the figure). Between the sled and the plane, the coefficient of static friction is 0.270, and the coefficient of kinetic friction is 0.140. (a) What is the minimum magnitude of the force , parallel to the plane, that will prevent the sled from slipping down the plane? (b) What is the minimum magnitude F that will start the sled moving up the plane? (c) What value of F is required to move the sled up the plane at constant velocity? (a) Number i (b) Number i (c) Number i Units Units Units +

You are working in an ice skating rink and have been asked to hang a new banner on the wall. Your friend is helping you so that the ladder does not collapse by exerting a force F_AL at an angle ϕ relative to the horizontal. The ladder has a length L and makes an angle of θ with respect to the vertical wall. You have a mass, m_Y, and are a horizontal distance x from the wall. The ladder has a mass of m_L. Because the wall is slick, and the ice on the floor is slick, the frictional forces acting on the ladder are negligible. Find a formula for the magnitude of the force that your friend must exert to keep the ladder from falling, in terms of the following variables: x,L,m_Y,m_L,θ,ϕ. Then use the following values to get a number for the magnitude of F_AL.   θ = 30.3 degrees ϕ = 23.028 degrees x = 1.491 meters L = 7.1 meters m_Y = 86.0 kg m_L = 42.14 kg Find the magnitudes of: F_AL, normal force of the wall on the ladder (N_WL), and normal force of the floor on the ladder (N_FL).

A rigid, vertical rod with a mass of 2.7 kg simply rests on the floor and is held in place by static friction. The coefficient of static friction between the rod and the floor is 1/6. The rod also has a wire connected between its top end and the floor, as shown in the figure. A horizontal force F is applied at the midpoint of the rod. F Æ 45° Find the greatest force F that can be applied at the midpoint of the rod without causing it to slip. N

A mass is on a slope with a coefficient of friction = 0.79. Slowly the angle of the slope is increased. What is the angle in degrees when the mass just starts to slide down the slope?

The figure shows a section of a cable-car system. The maximum permissible mass of each car with occupants is 2200 kg. The cars, riding on a support cable, are pulled by a second cable attached to the support tower on each car. Assume that the cables are taut and inclined at angle 0 = 39º. What is the difference in tension between adjacent sections of pull cable if the cars are at the maximum permissible mass and are being accelerated up the incline at 0.85 m/s²? Number Units Support cable- Pull cable

A 1520-N crate is to be held in place on a ramp that rises at 30.0° above the horizontal (see figure). The massless rope attached to the crate makes a 22.0° angle above the surface of the ramp. The coefficients of friction between the crate and the surface of the ramp are uk = 0.450 and ls = 0.650 The pulley has no appreciable mass or friction. What is the MAXIMUM weight w that can be used to hold this crate stationary on the ramp? w = ? 22.0° Crate Ramp 30.0°

A rock rests on a horizontal plane. The plane is slowly tilted so that the angle between the surface and the horizontal increases to 20 degrees, at which point the rock is about to slip. What is the coefficient of static friction between the rock and the surface, to two significant figures? O 0.36 2.2 3.4 9.4 O 13 O

A 150-lb block rests on a horizontal surface. The coefficient of static and kinetic frictions between the block and the surface are 0.30 and 0.20, respectively. What is the acceleration of the block when P = 90 lb. P μs=0.30, μk=0.20 150 lb

Two blocks, A and B (with mass 50 kg and 100 kg, respectively), are connected by a cord, as shown in Figure. The pulley has a negligible mass. The coefficient of kinetic friction between block A and the incline is = 0.11. The bloc B is maintained at rest at a height of 4 m, and the angle of the incline is 37°. The support of bloc B is removed and B starts to go down. woCalculate the velocity of the bloc B as it hits the ground. 50 kg 377 100 kg