A 60.0-kg mass person wishes to push a 120-kg mass box across a level floor.  The coefficient of static friction between the person's shoes and the floor is 0.700.  What is the maximum coefficient of static friction between the box and the floor such that the person can push horizontally on the box and cause it to start moving?

A block is placed on a wooden plank, which is initially horizontal.  One end of the plank is slowly raised to make it more and more inclined, and for a while the block stays in place on the plank and doesn't slide due to static friction.  Finally, when the plank reaches an incline of 56.3oabove horizontal, the block begins to slide.  What is the  coefficient of static friction between the block and the plank?

A horizontal force of 800 N is needed to overcome the force of static friction between a level floor and a 200-kg crate. If g = 9.8 m/s2 , what is the coefficient of static friction?

A 1.09 kg block is placed at one end of a wooden plank that is 2.02 m long. The plank is slowly tilted. M (a) The block starts to slide when the angle reaches 16 degrees. What is the coefficient of static friction between the block and the ramp? (b) The coefficient of kinetic friction between the block and the ramp is about 0.20. At what rate will the block accelerate down the plank if it is tilted at 16 μκ degrees?

A 50.0 N box is at rest on a horizontal surface. The coefficient of static friction between the box and the surface is 0.50, and the coefficient of kinetic friction is 0.30. A horizontal 20.0 N force is then exerted on the box. The magnitude of the acceleration of the box is most nearly  a 0.5 m/s2  b 1 m/s2  c 4 m/s2  d 0 m/s2

A block with mass m1 = 8.7 kg is on an incline with an angle θ = 37° with respect to the horizontal. The coefficients of friction are: μk = 0.36 and μs = 0.396. Another block with mass m2 = 15.5 kg is attached to the first block. The new block is made of a different material and has a greater coefficient of static friction. What minimum value for the coefficient of static friction is needed between the new block and the plane to keep the system from accelerating?

You managed to pull a heavy crate up a ramp on a truck. The crate has mass 45 kg. You were pulling with 478 N of force along the ramp while the ramp made an angle of theta=25.5 degrees with the horizontal. The coefficient of kinetic friction between the crate and the ramp is 0.47. What is the acceleration of the crate along the ramp?

A man is walking up a hill inclined at 24 degrees at constant speed while pulling a 23.6 kg box by a rope that is attached to it. If the angle the rope makes with the surface of the hill is 31 degrees and the coefficient of kinetic friction between the box and the hill is 0.10, what is the tension in the rope?

A block with a mass of 4.83 kg is at rest on an inclined surface. The surface makes an angle of  27.9° relative to horizontal. The coefficients of static and kinetic friction are 0.740 and 0.380 respectively. The block remains at rest. What is the magnitude of the frictional force that acts on the block?

A 620  kg packing crate is being pulled up a 16 degrees-inclined plane by a rope. The rope is parallel to the incline. The coefficient of kinetic friction is 0.3. (a) What is the size of the normal force acting on the crate? N (b) What is the size of the kinetic friction force acting on the crate? N (c) What is the size of the tension force if the crate is moving with constant velocity?