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Gyroscopes used in guidance systems to indicate directions in space must have an
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- What if another planet the same size as Earth were put into orbit around the Sun along with Earth. Would the moment of inertia of the system increase, decrease, or stay the same?arrow_forwardTwo children (m = 30.0 kg each) stand opposite each otheron the edge of a merry-go-round. The merry-go-round, whichhas a mass of 1.80 102 kg and a radius of 1.5 m, is spinningat a constant rate of 0.50 rev/s. Treat the two children and themerry-go-round as a system. a. Calculate the angular momentum of the system, treating each child as a particle. b. Calculatethe total kinetic energy of the system. c. Both children walkhalf the distance toward the center of the merry-go-round. Calculate the final angular speed of the system.arrow_forwardSection 11.5 The Motion of Gyroscopes and Tops A spacecraft is in empty space. It carries on board gyroscope with a moment of inertia of Ig = 20.0 kgm2 about the axis of the gyroscope. The moment of inertia of the spacecraft around the same axis is Is = 5.00 X 105 kgm2. Neither the spacecraft nor the gyroscope is originally rotating. The gyroscope can be powered up in a negligible period of time to an angular speed of 100 rad/s. If the orientation of the spacecraft is to be changed by 30.0, for what time interval should the gyroscope be operated?arrow_forward
- One method of pitching a softball is called the wind-mill delivery method, in which the pitchers arm rotates through approximately 360 in a vertical plane before the 198-gram ball is released at the lowest point of the circular motion. An experienced pitcher can throw a ball with a speed of 98.0 mi/h. Assume the angular acceleration is uniform throughout the pitching motion and take the distance between the softball and the shoulder joint to be 74.2 cm. (a) Determine the angular speed of the arm in rev/s at the instant of release, (b) Find the value of the angular acceleration in rev/s2 and the radial and tangential acceleration of the ball just before it is released, (c) Determine the force exerted on the ball by the pitchers hand (both radial and tangential components) just before it is released.arrow_forwardWhy is the following situation impossible? A space station shaped like a giant wheel has a radius of r = 100 m and a moment of inertia of 5.00 108 kg m2. A crew of 150 people of average mass 65.0 kg is living on the rim, and the stations rotation causes the crew to experience an apparent free-fall acceleration of g (Fig. P10.52). A research technician is assigned to perform an experiment in which a ball is dropped at the rim of the station every 15 minutes and the time interval for the ball to drop a given distance is measured as a test to make sure the apparent value of g is correctly maintained. One evening, 100 average people move to the center of the station for a union meeting. The research technician, who has already been performing his experiment for an hour before the meeting, is disappointed that he cannot attend the meeting, and his mood sours even further by his boring experiment in which every time interval for the dropped ball is identical for the entire evening.arrow_forwardA bicycle is turned upside down while its owner repairs a flat tire. A friend spins the other wheel and observes that drops of water fly off tangentially. She measures the heights reached by drops moving vertically (Fig. P7.8). A drop that breaks loose from the tire on one turn rises vertically 54.0 cm above the tangent point. A drop that breaks loose on the next turn rises 51.0 cm above the tangent point. The radius of the wheel is 0.381 m. (a) Why does the first drop rise higher than the second drop? (b) Neglecting air friction and using only the observed heights and the radius of the wheel, find the wheels angular acceleration (assuming it to be constant). Figure P7.8 Problems 8 and 69.arrow_forward
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