An air puck of mass m1 = 0.25 kg is tied to a string and allowed to revolve in a circle of radius R = 1.0 m on a frictionless horizontal table. The other end of the string passes through a hole in the center of the table, and a mass of m2 = 1.0 kg is tied to it (Fig. P7.27). The suspended mass remains in equilibrium while the puck on the tabletop revolves. (a) What is the tension in the string? (b) What is the horizontal force acting on the puck? (c) What is the speed of the puck?

A horizontal circular platform rotates counterclockwise about its axis at the rate of 0.885 rad/s. You, with a mass of 73.7 kg, walk clockwise around the platform along its edge at the speed of 1.17 m/s with respect to the platform. Your 20.3 kg poodle also walks clockwise around the platform, but along a circle at half the platform's radius and at half your linear speed with respect to the platform. Your 17.5 kg mutt, on the other hand, sits still on the platform at a position that is 3/4 of the platform's radius from the center. Model the platform as a uniform disk with mass 91.9 kg and radius 1.99 m. Calculate the total angular momentum of the system. total angular momentum: kg · m2/s

There is a clever kitchen gadget for drying lettuce leaves after you was them. It consists of a cylindrical container mounted so that it can be rotated about its axis by turning a hand crank. The outer wall of the cylinder is perforated with small holes. You put the wet leaves in the container and turn the crank to spin off the water. The radius of the ontainer is 11.4 cm. When the cylinder is rotating at 1.36 revolutions per second, what is the magnitude of the centripetal acceleration of the outer wall?

A block (mass = 3.0kg) is hanging from a mass-less string that is wrapped around a pulley. The string is 120cm long. Initially the string was wrapped fully and the pulley is prevented from rotating and the block is stationary. Then, the pulley is allowed to rotate as the block falls. Assume that the radius of the cord around the pulley remains constant at a value of 0.050m during the block's descent. The mass rolls from rest down to the end of the string. Find the transnational kinetic energy. Find the rotational kinetic energy. Find the angular speed.

A small block of mass m2 hangs from a massless rope wrapped around a pulley with radius of R. The moment of inertia of the entire pulley is I = 4m2(R)². Another block m1=2m2 is connected to the outer cylinder of the pulley via a horizontal massless rope. The coefficient of kinetic friction between the block and the horizontal surface is µ; = (i.e. the frictional force is f = }mg). When m2 is released from rest, what is the angular acceleration a of the block and pulley system? T, m, T. m, Pick the correct answer 最 3 g 20

A puck of mass m = 1.10 kg slides in a circle of radius r = 19.0 cm on a frictionless table while attached to a hanging cylinder of mass M = 2.20 kg by a cord through a hole in the table. What speed keeps the cylinder at rest? m/s

A turntable (disk) of radius r= 25.0 cm and rotational inertia 0.395 kg · m rotates with an angular speed of 3.04 rad/s around a frictionless, vertical axle. A wad of clay of mass m = 0.254 kg drops onto and sticks to the edge of the turntable. What is the new angular speed of the turntable? rad/s

A child's top is held in place upright on a frictionless surface. The axle has a radius of r = 4.21 mm. Two strings are wrapped around the axle, and the top is set spinning by applying T = 3.15 N of constant tension to each string. If it takes 0.440 s for the string to unwind, how much angular momentum L does the top acquire? Assume that the strings do not slip as the tension is applied. L = kg.m² S Point P is located on the outer surface of the top, a distance h = 33.0 mm above the ground. The angle that the outer surface of the top makes with the rotation axis of the top is 0 = 17.0°. If the final tangential speed v₁ of point P is 1.75 m/s, what is the top's moment of inertia I? I = kg.m² T 2r R 2r P T T

A horizontal circular platform rotates counterclockwise about its axis at the rate of 0.961 rad/s. You, with a mass of 66.5 kg, walk clockwise around the platform along its edge at the speed of 1.11 m/s with respect to the platform. Your 20.5 kg poodle also walks clockwise around the platform, but along a circle at half the platform's radius and at half your linear speed with respect to the platform. Your 18.3 kg mutt, on the other hand, sits still on the platform at a position that is 3/4 of the platform's radius from the center. Model the platform as a uniform disk with mass 92.9 kg and radius 1.93 m. Calculate the total angular momentum of the system.

A horizontal force of 170 N is required to push a 180-kg refrigerator across a level linoleum floor. The refrigerator rolls on four 50-mm-diameter plastic wheels. Neglect all friction except rolling resistance and determine the coefficient of rolling friction between the plastic wheels and the linoleum floor.