A chair of weight 120 N lies atop a horizontal floor; the floor is not frictionless. You push on the chair with a force of FFF = 42.0 N directed at an angle of 35.0 ∘ below the horizontal and the chair slides along the floor. Using Newton's laws, calculate n, the magnitude of the normal force that the floor exerts on the chair.

In the figure, a crate of mass m = 110 kg is pushed at a constant speed up a frictionless ramp (0 = 26°) 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 47.798 (b) Number i 109.05 Units Units ‒‒‒‒‒ e N N m

A 31 kg child goes down a straight slide inclined 38∘∘ above horizontal. The child is acted on by his weight, the normal force from the slide, and kinetic friction. How large is the normal force of the slide on the child? Express your answer with the appropriate units.   n=?

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A 16 kg block of steel is at rest on a horizontal table. The coefficient of static friction between block and table is 0.54. (a) What is the magnitude of the horizontal force that will put the block on the verge of moving? 84.7 N (b) What is the magnitude of a force acting upward 60° from the horizontal that will put the block on the verge of moving? X N (c) If the force acts down at 60° from the horizontal, how large can its magnitude be without causing the block to move? N

A block of mass = 50.0 kg is being dragged at a constant velocity across a floor by a strong person pulling it with a rope. The rope makes an angle of 300 with the horizontal. The tension in the rope is 50.0 Newtons. Assume a real floor, with friction. What is the coefficient of kinetic friction between the box and the floor?

A mysterious force acts on all particles along a particular line and always points towards a particular point P on the line. The magnitude of the force on a particle increases as the cube of the distance from that point, that is, F∝ r3, if the distance from the P to the position of the particle is r. It has been determined that the constant of proportionality is 0.23 N/m3, i.e. the magnitude of the force on a particle can be written as 0.23r3, when the particle is at a distance r from the force center. Find the magnitude of the potential energy, in joules, of a particle subjected to this force when the particle is at a distance 0.21 m from point P assuming the potential energy to be zero when the particle is at P.  PE= ?

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?       (a) The force of friction on the crate is mgμs.       (b) The force of friction on the crate is mgμk.       (c) The force of friction on the crate is greater than the force that the worker exerts on the crate.           (d) The force exerted on the worker by the crate is equal in magnitude to the force of friction exerted by the surface on the crate.

Two roofers are installing a new roof. Bob is sitting on the top of the roof that is angled at 23.5 degrees from the horizontal. Nate is sitting 4.1 m further down the roof. In order to get a box of shingles to Nate, Bob just slides the box directly down to him. If the coefficient of kinetic friction for the box and roof is 0.5, then with what speed should Bob initially push the box so that it slides to a stop right as it reaches the Nate?

Crates A and B have equal mass. Crate A is at rest on an incline that makes and angle of theta = 22.22 degrees horizontal, while crate B is at rest on a horizontal surface.   Write an expression for the ratio fo the normal forces, A to B in terms of theta?