The figure below shows 2 blocks.  The upper block has a mass of 4.0 kg and the lower block has a mass of 3.0 kg.  The friction coefficient between the lower block and the ground is 0.60.  The friction coefficient (static and kinetic) between the 2 blocks is 0.71.  Determine the force necessary to cause the maximum acceleration possible without the upper block slipping.

F(t) Force_Crate Known values: Mass of Block 68 kg TT Hs μk 0 0.63 0.53 26° Problem Statement: A crate is initially at rest on a sloped surface, when a force is applied: F(t) where t is in seconds. Answers: When t=44.47 seconds, the crate has not yet started moving. Find the magnitude of the friction force at that time: 317.771 N The direction of the friction force at that time is: down the slope Find the time required for the crate to start moving: Find the crate's speed when t=174.9 s: 9.485 m/s Be sure to include units with your answers. 169.756 S 240+0.2 N,

The coefficient of kinetic friction between a box and the floor is μk = 0.14 and the coefficient of static friction is μs = 2.0μk. Calculate the ratio of static to kinetic friction force if m = 8 kg.

A 2.88 kg mass begins at rest and slides 2.84 m down an incline of 49.6 degree in a time of 1.61 s. What is the coefficient of kinetic friction regarding this system if only the force due to gravity, the force of kinetic friction, and the normal force are considered? Enter a number rounded to 3 decimal places

A 37.5 kg block is pushed at a constant speed up a 24.0° incline by an applied force parallel to the incline. If the coefficient of kinetic friction between the block and the incline is 0.340, find the magnitude of the applied force.

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?

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 2.03 kg book is placed on a flat desk. Suppose the coefficient of static friction between the book and the desk is 0.482 and the coefficient of kinetic friction is 0.262. How much force is needed to keep the book moving at a constant speed once it begins moving?

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