A 769-kg crate is placed on an adjustable inclined plane. As one end of the incline is raised, the crate begins to move downward. If the crate slides down the plane with an acceleration of 0.19 m/s? when the incline angle is 36°, what is the coefficient of kinetic friction between ramp and crate? (g = 9.8 m/s2)

Many birds can attain very high speeds when diving. Using radar, scientists measured the altitude of a barn swallow in a vertical dive; it dropped 208 m in 3.0 s. The mass of the swallow was estimated to be 0.018 kg, and its cross-section area as 5.6 x 10-4 m2. What was the drag coefficient for this swallow as it dove?

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 1500-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 us = 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? %3D W= ? Crate 22.0° Ramp 30.00

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?

Mary applies a force of 76 N to push a box with an acceleration of 0.40 m/s2. When she increases the pushing force to 84 N, the box's acceleration changes to 0.62 m/s2. There is a constant friction force present between the floor and the box. (a) What is the mass of the box in kilograms? kg (b) What is the coefficient of kinetic friction between the floor and the box?

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

Two crates of fruit  are released from the top of a ramp inclined at 30 degrees from the horizontal and 4.5 meter long. The two crates consist of  an apple crate of mass 20 kg that is placed in front of a watermelon crate of mass 80 kg.  The apple crate has a coefficient of friction of 0.20 while the watermelon crate has a coefficient of friction of 0.15. How long does it take the apple crate to reach the bottom of the incline if it needs to travel a distance of 4.5 meters?

A book slides across a level, carpeted floor with an initial speed of 3.85 m/s and comes to rest after 3.75 m. Calculate the coefficient of kinetic friction μ between the book and the carpet. Assume the only forces acting on the book are friction, weight. and the normal force. H =

A tractor is speeding up at 3 m/s/s while pulling a 744 kg sled with a rope at an angle of 34 degrees. The coefficient of kinetic friction between the sled and ground is 0.5. What is the tension (Newtons) in the rope? (g=9.8 m/s2)