1. A dockworker is loading 20.2-kg crates onto a ship. He notices that it takes 77.2 Newtons of horizontal force to set them into motion from rest. Once in motion, it takes 58.3 Newtons of horizontal force to keep them moving at a constant speed. Determine the coefficient of static friction. Enter your answer accurate to the third decimal place.

(Referring to the previous problem.) Determine the coefficient of kinetic friction. Enter your answer accurate to the third decimal place.

2. A box rests on the back bed of a truck. The coefficient of friction between the box and the surface is .789. Calculate the maximum acceleration (in m/s/s) that the truck can have before the box will slide along the truck bed.

3. Consider the free-body diagram shown at the right. If the applied force is 58.1 N at an angle of 23 degrees, the force of gravity is 127.2 N and the coefficient of friction is .626, then what is the acceleration (in m/s/s) of the object. Is it a negative value for a leftward acceleration?

4. A box of books weighing 304 N is shoved across the floor of an apartment by exerting a force of 443 N downward at angle of 35.2 degrees below the horizontal . If the coefficient of kinetic friction is .572, how long (in seconds) does it take the box to move 2.99 meters.

5. A man doing his spring cleaning pulls a 151-N vacuum cleaner across the floor at a constant velocity of 1.13 m/s by exerting a force on it at an angle of 35.4 degrees above the horizontal. If he must pull with a force of 35.5 N to move the vacuum cleaner, what is the coefficient of friction between the vacuum cleaner and the floor? Enter your answer accurate to the fourth decimal place.

6. A student slides a 1323 N crate across the floor by pulling with a force of 761 N at an angle of 30.8 degrees with the horizontal. If the crate moves at a constant speed, find the coefficient of sliding friction between the crate and the floor. Enter your answer accurate to the fourth decimal place.

A block of mass m1 = 4.70 kg sits on top of a second block of mass m2 = 16.3 kg, which in turn is on a horizontal table. The coefficients of friction between the two blocks are µs = 0.300 and µk = 0.100. The coefficients of friction between the lower block and the rough table are µs = 0.600 and µk = 0.500. You apply a consta

A 17.2 kg box is released on a 38.1 degree incline and accelerates down the incline at 0.269 m/s^2. Find the friction force impeding its motion, and the coefficient of friction.

(Please see the attached file for detailed problem and fig.)
The two blocks, m1 = 3.0 kg and m2 = 4.9 kg, in the figure (see attachment) are connected by a massless rope that passes over a pulley. The pulley is 12 cm in diameter and has a mass of 2.0 kg. As the pulley turns, friction at the axle exerts a torque of magnitude 0

The weight of the block in the drawing is 80.2 N. The coefficient of static friction between the block and the vertical wall is 0.490.
(a) What minimum force F is required to prevent the block from sliding down the wall?
(b) What minimum force is required to start the block moving up the wall?

The sled dog in figure drags sleds A and B across the snow. The coefficient of friction between the sleds and the snow is 0.10.
a.) If the tension in rope 1 is 150 N, what is the tension in rope 2?
Answer: =? N

A crate is resting on a ramp that is inclined at an angle above the horizontal. As it increased, the crate remains in place until it reaches a value of 29.2°. Then the crate begins to slide down the slope.
(a) Determine the coefficient of static friction between the crate and the ramp surface.
(b) The coefficient of kinet

1. A father pulls his young daughter on a sled with constant velocity on a level surface through a distance of 25 m. The total mass of the sled and the girl is 45 kg and the coefficient of kinetic friction between the sled runners and the snow is .35
The force exerted by the man is applied at an angle of 30 degrees with resp

1) Sally expends 10460 J of energy to drag a wooden crate 24.7 m across a floor with a constant speed. The rope makes an angle of 48.0° with the horizontal.
(a) How much force does the rope exert on the crate?
_____ N
(b) What is the force of friction acting on the crate to impede its motion?
Magnitude
_________ N

The floor of a railroad flatcar is loaded with loose crates having a coefficient of static friction of 0.48 with the floor. If the train is initially moving at a speed of 52 km/h, in how short a distance can the train be stopped at constant acceleration without causing the crates to slide over the floor?

If an object slides directly down an inclined place, at a constant velocity of 6 m/s, how large is the coefficient of kinetic friction if the plane make an angle of 25 degrees with the horizontal?