A skateboarder is attempting to make a circular arc of radius r = 11 m in a parking lot. The total mass of the skateboard and skateboarder is m = 86 kg. The coefficient of static friction between the surface of the parking lot and the wheels of the skateboard is μs = 0.59 . He speeds up very slightly and begins to slide. The coefficient of kinetic friction is μk = 0.21. What is the new magnitude of his radial acceleration in m/s2?

A block with some mass m is connected to a string that is attached to the ceiling. The block on the end of the string is going around a circular path with a constant radius r and constant speed.  Applying Newton's second law to the x and y components of forces seperately in order to find the expressions for the tension of the string in terms of mass m, angle θ, and constant g.

A hockey puck with mass 0.225 kg is at rest at the origin (x = 0) on the horizontal, frictionless surface of an ice rink. At time t = 0 a player applies a force of 9.50 N on the puck, parallel to the positive x- axis. She continues to apply this force until t = 0.850s. What are the position and speed of the puck at t = 0.850 s?

At t = 0, a cart of mass m = 5 kg starts rolling down an incline, making an angle α = 20o with the horizontal. Initially the cart rolls down with no friction, but after traveling a distance of ∆ = 10 m it encounters a rough surface, where the coefficient of friction is k = 0.45. Find the acceleration of the cart along the incline (positive direction is downhill) after it encounters the rough surface.   A.9.8 m/s2  B.9.2 m/s2  C.7.7 m/s2  D.3.6 m/s2  E.3.4 m/s2  F.-0.8 m/s2

The 1.0 kg block in the figure is tied to the wall with a rope. It sits on top of the 2.0 kg block. The lower block is pulled to the right with a tension force of 20 N. The coefficient of kinetic friction at both the lower and upper surfaces of the 2.0 kg block is μkμk = 0.42. What is the acceleration of the 2.0 kg block? Express your answer with the appropriate units.

A girl swings a 0.190 kg rock attached to a taut string in a circle around her head; her hand holds the end of the string above her head, and the string angles down slightly. The string is massless and 0.680 m long. A coordinate system lies with its origin at the location where the string comes out of the girl's hand. The positive z-axis points vertically upwards, the positive y- axis points horizontally towards the right, and the positive x-axis points out of the screen. At a certain instant, the rock makes 3.25 revolutions per second (rev/s) in a counterclockwise direction, as seen from above. The string is inclined at an angle of 0 = 12.4° below the xy-plane, and the projection of the string onto the xy- plane makes an angle o = 36.8° with the positive x-axis. What is the tangential velocity vector v in meters per second (m/s) at this instant? Report your answer using ijk unit vector notation. i = v, i + vyj+ vz k m/s

A small object is initially at rest at the top of a large solid sphere that is fixed on the ground. The small object then begins to slide along the surface of the large solid sphere, without friction. V₁ = 0 RI Part (a) Find the angle at which the small object loses contact with the large solid sphere. Part (b) Find the maximum horizontal distance traveled by the small object before it hits the ground. Take (xi, y₁) = (0,2R) as the coordinates for the top of the large solid sphere.

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In the figure, three masses are attached by cords that loop over frictionless pulleys. Block B lies on a frictionless table. mA = 5.4 kg, mB = 6.2 kg, and mc = 10.7 kg. Find the tension in the cord to the right (between masses B and C) once the blocks have been released and are free to move. Your answer should be in N: Question Help: Read B

V F Resolve the force F into components along the u and v axes, and determine the magnitudes of these components. Given that F = 35 N, a = 16° , and ß = 32°, the magnitude along u is (round to one decimal place) : N the magnitude along v is (round to one decimal place) : N