An object of mass 3.1 kg with a certain initial speed on a horizontal surface comes to rest after traveling a distance of 15.9 m. If the coefficient of kinetic friction between the object and the horizontal surface is 0.27, what is the initial speed of the object? Express your answer in m/s, to at least one digit after the decimal point.

A Box is placed on a 40° slope with a coefficient of friction of 0.30. The box starts approximately at 6.0m off the ground. It slides onto a horizontal part with a coefficient of 0.45. How far does it slide along this part?

You drop an object of mass m from a tall building. Suppose the only forces affecting its motion are gravity, and air resistance proportional to the object's speed with positive constant of proportionality k. Let g denote gravitational acceleration (a positive constant). Express the total force in terms of m, g, and the object's velocity v, where upward displacement is considered positive. F = mg - kv Newton's second law tells us that force is equal to mass x acceleration, F = ma. Relating acceleration to velocity, rewrite the equation for total force above as a first order differential equation for v as a function of t. Denote v' as dv dt v(t) m(- dr) this is not an equation. Solve this differential equation for v(t) with the initial condition v(0) = V0. = mg (1-e ==) m k Find the terminal Terminal velocity = mg k X velocity. X syntax error: X X

Fnorm (normal force) = __________ N Ffrict (force of friction) = __________ N m (mass) = _________ kg a (acceleration) = __________  m/s/s ΣF (net force) = __________ N

A mass is suspended from the ceiling in an elevator by a heavy rope. The mass is 80 kg and the mass of the rope is 2 kg. If the breaking strength of the rope is 1000 N, what is the maximum acceleration of the elevator such that the rope will not break?

A 1.4 gram bullet is shot into a tree stump. It enters at a velocity of 341 m/sec and comes to rest after having penetrated the stump in a straight line. It takes 0.00032 sec to come to a stop after striking the stump. What was the force on the bullet during impact?  (answer in Newtons)

Mary applies a force of 73 N to push a box with an acceleration of 0.42 m/s2. When she increases the pushing force to 83 N, the box's acceleration changes to 0.59 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 coin is resting on the surface of a closed book. As you slowly open the cover, the coin remains in place (it doesn't slide). When the book's cover is open 14 degrees, the coin finally starts sliding down. What is the coefficient of static friction between the book and the coin?   Answer to 3 decimal places (e.g. 0.123).

Determine the force Q-> when the block moves with constant velocity. Express your answer in vector form.

We often think of friction and air resistance as forces that we want to minimize because they can hinder the motion of an object.  But they are not always undesirable, and in fact, can be an essential element in a machine or process. Identify one or two applications that depend on friction and air resistance.  Explain how friction or air resistance works in those situations and what would happen if there were no friction or air resistance.  Your initial post should be 75-150 words in length and is due on Sunday.