The three diagrams below show a block of mass m being pulled or pushed at constant acceleration a, along a table with a force P. The coefficient of kinetic friction is u,. What is the friction force in each case? Give your answer in terms of the pushing force P, a, m, and the angle 0. (i) (ii) (iii) case (i) Did you draw a free-body diagram for this situation and identify all the forces acting on the object? What is Newton's Second Law for motion in the horizontal direction? case f = uk· (m ·g+P•sin – ) (ii) fk = uk · (m·g - P.sin – ) case (ii) Additional Materials

A block is pushed up a ramp and is observed to accelerate up the block as is shown in the figure below.  The friction coefficient between the block and the ramp is mu. Write an expression for the acceleration of the block in terms of F, theta, m, g and mu.

Part A Make a free-body diagram of the box B. Draw the force vectors with their tails at the dot. Part B Make a free-body diagram of the box A. Draw the force vectors with their tails at the dot.

Two blocks are connected by a massless rope. The rope passes over an ideal (frictionless and massless) pulley such that one block with mass m1 = 12.25 kg is on a horizontal table and the other block with mass m2 = 7.5 kg hangs vertically. Both blocks experience gravity and the tension force, T. Use the coordinate system specified in the diagram. a.)  Assuming friction forces are negligible, write an expression, using only the variables provided, for the acceleration that the block of mass m1 experiences in the x-direction. Your answer should involve the tension, T. b.)  Under the same assumptions, write an expression for the acceleration, a2, the block of mass m2 experiences in the y-direction. Your answer should be in terms of the tension, T and m2. c.) Carefully consider how the accelerations a1 and a2 are related. Solve for the magnitude of the acceleration, a1, of the block of mass m1, in meters per square second. d.)Find the magnitude of the tension in the rope, T, in newtons.

The two trees in (Figure 1) are 7.1 m apart. A backpacker is trying to lift his 29-kg backpack out of the reach of bears. Part A Calculate the magnitude of the force F that he must exert downward to hold the backpack so that the rope sags at its midpoint by 1.3 m. Express your answer to two significant figures and include the appropriate units. F = Submit Part B for Part A for Part do for Part redo for Part A reset for Part A keyboard shortcuts for Part A help for Part A Value F = Request Answer Calculate the magnitude of the force F that he must exert downward to hold the backpack so that the rope sags at its midpoint by 0.13 m. Express your answer to two significant figures and include the appropriate units. Units Value for Part B for Part B do for Part th redo for Part B resetor Part B keyboard shortcuts for Part B help for Part B Units

A skier is standing on a 30o hill.  Draw the hill and add idealized force vectors that represent the force of the skier (FS), the normal force (FN), and the force of friction (FF).

A 1,040-N crate is being pushed across a level floor at a constant speed by a force  F  of 390 N at an angle of 20.0° below the horizontal, as shown in the figure a below. Two figures show a side view of a crate positioned upon a horizontal surface. Figure (a): An arrow pointing downward and to the right is labeled vector F and forms an angle of 20° below the horizontal as it approaches the upper left edge of the crate. Figure (b): An arrow pointing upward and to the right is labeled vector F and forms an angle of 20° above the horizontal as it extends from the upper right edge of the crate. (a) What is the coefficient of kinetic friction between the crate and the floor? (Enter your answer to at least three decimal places.)(b) If the 390-N force is instead pulling the block at an angle of 20.0° above the horizontal, as shown in the figure b, what will be the acceleration of the crate? Assume that the coefficient of friction is the same as that found in part (a).

A 1,380-N crate is being pushed across a level floor at a constant speed by a force F of 320 N at an angle of 20.0° below the horizontal, as shown in the figure a below. a) What is the coefficient of kinetic friction between the crate and the floor? (Enter your answer to at least three decimal places.)(b) If the 320-N force is instead pulling the block at an angle of 20.0° above the horizontal, as shown in the figure b, what will be the acceleration of the crate? Assume that the coefficient of friction is the same as that found in part (a).m/s2

A bag of cement weighing 525 N hangs in equilibrium from three wires as suggested in the figure below. Two of the wires make angles ?1 = 61.0° and ?2 = 42.0° with the horizontal. Assuming the system is in equilibrium, find the tensions T1, T2, and T3 in the wires. T1 = N T2 = N T3 =.

The pair of pulleys is used to lift a 40-kg block 0.25 m. The constant upward acceleration of the block during the lift is +2.5 m/s^2, and the pulleys and rope have negligible inertia and negligible friction. A. What is the tension in the pulling rope? Express your answer with the appropriate units. B. What is the tension in the rope from which the block hangs? Express your answer with the appropriate units. C. Determine the magnitude of the force exerted by the upper mount on the top pulley. Express your answer with the appropriate units. D. How much work is done by the person pulling the rope in lifting the block 0.25 mm? Express your answer with the appropriate units. E. By how much does the kinetic energy of the block change in this process? Express your answer with the appropriate units. F. How much work is done on the block by the rope attached to it? Express your answer with the appropriate units. G. How much work does the ceiling do in this process? Express your answer with the…