A crate is sitting on a horizontal surface where the coefficient of static friction is 0.60. A worker pushes horizontally on the crate, which has a mass of 45 kg. The crate does not move, and there are no other forces acting on it. Which of the following statements is true?

Mary applies a force of 77 N to push a box with an acceleration of 0.55 m/s2. When she increases the pushing force to 85 N, the box's acceleration changes to 0.71 m/s2. There is a constant friction force present between the floor and the box. (a) What the mass of the box in kilograms? kg (b) What is the coefficient of kinetic friction between the floor and the box?

A block 5.0 kg is on an inclined plane.  If the friction coefficient (static and kinetic) between the block and the plane is μ = 0.5,  and the angle θ = 35°, determine the maximum friction force that the plane could exert on the block.  The block is not necessarily at rest.  Use g = 10 N/kg.

In the figure, a crate of mass m = 83 kg is pushed at a constant speed up a frictionless ramp (0 = 32°) by a horizontal force F. The positive direction of an x axis is up the ramp, and the positive direction of a y axis is perpendicular to the ramp. (a) What is the magnitude of F? (b) What is the magnitude of the normal force on the crate? (a) Number (b) Number i Units Units

A box is at rest on a floor. The box has a mass of 35.0 kg. A force P = 213.0 N is acting to the left at an angle = 31.5° above the horizontal as shown in the figure provided on the right. Between the box and the floor, the coefficient of static friction is Hs = 0.830 and the coefficient of kinetic friction is HK = 0.778. What is the magnitude of the normal force acting on the box? P 0 m

Three forces act on a moving object. One force has a magnitude of 75.5 N and is directed due north. Another has a magnitude of 6 7.0 N and is directed due west. What must be (a) the magnitude and (b) the direction of the third force, such that the object continues to move with a constant velocity? Express your answer as a positive angle south of east. (a) Number i (b) Number i Units Units

A 2.5 kg block is initially at rest on a horizontal surface. A horizontal force F of magnitude 6.2 N and a vertical force P are then applied to the block. The coefficients of friction for the block and surface are us = 0.38 and uk = 0.22. (a) Determine the magnitude of the frictional force acting on the block if the magnitude of P is 8.0 N. (b) Determine the magnitude of the frictional force acting on the block if the magnitude of P is 10.0 N. (c) Determine the magnitude of the frictional force acting on the block if the magnitude of P is 12.0 N.

The force acting on a particle has a magnitude of 166 N and is directed 29.4° above the positive x-axis. (a) Determine the x-component of the force.  (b) Determine the y-component of the force.

In the figure, a crate of mass m = 88 kg is pushed at a constant speed up a frictionless ramp (0 = 30°) by a horizontal force F.The positive direction of an x axis is up the ramp, and the positive direction of a y axis is perpendicular to the ramp. (a) What is the magnitude of F? (b) What is the magnitude of the normal force on the crate? (a) Number 497.91 Units (b) Number i 995.82 Units