A conveyor is dumping sand onto a cone shaped pile. Given that the coefficient of static friction between the sand grains is μs, what is the maximum angle θ?

A moving truck (m = 3200 kg) is parked on a hill that is inclined at an angle of 11◦ from the horizontal. Assuming that the static friction between the truck and surface on which it is parked is at its maximum value, what is the coefficient of static friction of the surface?

You are given the job of moving a refrigerator with a mass of 1.8 x 102 kg across a horizontal floor. The coefficient of static friction between the refrigerator and the floor is 0.45. Calculate the magnitude of the minimum force that is required just to set the refrigerator into motion.

A constant force Fa pushes a 22.5-kg box across a rough horizontal surface. The magnitude of Fa is 185 N and the force is inclined at an angle of θ = 30.0° below the horizontal. The coefficient of kinetic friction between the box and the surface is μk = 0.500. What is the magnitude of the box's acceleration?

A 100 kg block is at rest on a flat floor with a coefficient of static friction 0.62. A horizontal force of 3.7 N is applied to the block, but it does not budge. What is the magnitude of the frictional force on the block applied?

BOGART IS AN ADVENTUROUS MAN. HE WANTS TO CROSS THE 12-FT PLANK, WHICH COEFFICIENT OF FRICTION AT THE CONTACT POINTS A AND B IS µs = 0.4. AT WHAT DISTANCE x WILL BOGART START TO REALIZE THAT NOT EVERYTHING IN LIFE IS AN ADVENTURE (HE WILL REALIZE THE PLANK WILL SLIP!). ASSUME BOGART'S WEIGHT AS 85 LB. В 45° 15° 60°

A 7.5 kg backpack is sliding across the floor.  The coefficient of friction between the backpack and the floor is 0.20.  Answer the following:   Is this static or kinetic friction?

Problem 1: While training on the planet Dagobah, Luke Skywalker is asked by Yoda to hold a block with a mass of 6.80kg against a vertical wall using only the Force. Luke applies the Force with a magnitude of 115.0N at an angle of 52.0° with respect to the horizontal. Luke discovers that if the Force increases any more, the block begins to slide up the wall. What is the coefficient of static friction between the block and the wall? Assume that gravity on Dagobah is the same as gravity on Earth.

A block is at rest on a horizontal floor. There is friction between the block and the floor. The block has a mass = 5.00 kg. A horizontal force of 13.0 Newtons is applied to the block and the block starts to move in the direction of the force. What is the coefficient of static friction?

A roller-coaster car is towed up an incline at a steady speed of 0.500 m/s by a chain parallel to the surface of the incline. The slope is 3.00%, which means that the elevation increases by 3.00 m for every 100.0 m of horizontal distance. The mass of the roller-coaster car is 594 kg. Ignoring friction, what is the magnitude of the force exerted on the car by the chain?