Concept explainers
CP A large turntable with radius 6.00 m rotates about a fixed vertical axis, making one revolution in 8.00 s. The moment of inertia of the turntable about this axis is 1200 kg · m2. You stand, barefooted, at the rim of the turntable and very slowly walk toward the center, along a radial line painted on the surface of the turntable. Your mass is 70.0 kg. Since the radius of the turntable is large, it is a good approximation to treat yourself as a point mass. Assume that you can maintain your balance by adjusting the positions of your feet. You find that you can reach a point 3.00 m from the center of the turntable before your feet begin to slip. What is the coefficient of static friction between the bottoms of your feet and the surface of the turntable?
Want to see the full answer?
Check out a sample textbook solutionChapter 10 Solutions
University Physics with Modern Physics, Books a la Carte Edition; Modified MasteringPhysics with Pearson eText -- ValuePack Access Card -- for ... eText -- Valuepack Access Card (14th Edition)
Additional Science Textbook Solutions
Applied Physics (11th Edition)
Modern Physics
University Physics (14th Edition)
The Cosmic Perspective (8th Edition)
Lecture- Tutorials for Introductory Astronomy
College Physics (10th Edition)
- A centrifuge used for training astronauts rotating at 0.810 rad/s is spun up to 1.81 rad/s with an angular acceleration of 0.050 rad/s2. a. What is the magnitude of the angular displacement that the centrifuge rotates through during this increase in speed? b. If the initial and final speeds of the centrifuge were tripled and the angular acceleration remained at 0.050 rad/s2, what would be the factor by which the result in part (a) would change?arrow_forwardYou have a grindstone (a disk) that is 198.641 kg, has a 0.699-m radius, and is turning at 97.425 rpm, and you press a steel axe against it with a radial force of 89.000 N. Assuming the stone makes 6 turns before coming to rest. What is the the kinetic coefficient of friction between steel and stone? The moment of inertia of the grand stone is 1/2*mass*(radius)2arrow_forwardA horizontal circular platform rotates counterclockwise about its axis at the rate of 0.947 rad/s. You, with a mass of 75.1 kg, walk clockwise around the platform along its edge at the speed of 1.09 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 18.9 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 92.7 kg and radius 1.95 m. Calculate the total angular momentum of the system. total angular momentum: kg · m?/sarrow_forward
- A horizontal circular platform rotates counterclockwise about its axis at the rate of 0.941 rad/s. You, with a mass of 70.9 kg, walk clockwise around the platform along its edge at the speed of 1.03 m/s with respect to the platform. Your 21.1 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 17.3 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 90.9 kg and radius 1.83 m. Calculate the total angular momentum of the system. total angular momentum: 206.521 kg · m²/sarrow_forwardA figure skater has a moment of inertia of 0.33 kg-m2. He is spinning at 336.4 rpm. He extends his arms until he slows down to 74.3 rpm. What is his new moment of inerta (in kg-m2)?arrow_forwardA horizontal circular platform rotates counterclockwise about its axis at the rate of 0.989 rad/s. You, with a mass of 70.1 kg, walk clockwise around the platform along its edge at the speed of 1.05 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 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 1.97 m. Calculate the total angular momentum Ltot of the system. Ltot = kg-m²/sarrow_forward
- A horizontal circular platform rotates counterclockwise about its axis at the rate of 0.851 rad/s. You, with a mass of 72.5 kg,walk clockwise around the platform along its edge at the speed of 1.05 m/s with respect to the platform. Your 20.9 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 17.7 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 90.7 kg and radius 1.99 m. Calculate the total angular momentum ?tot of the system.arrow_forwardA skateboarder is attempting to make a circular arc of radius r = 14 m in a parking lot. The total mass of the skateboard and skateboarder is m = 89 kg. The coefficient of static friction between the surface of the parking lot and the wheels of the skateboard is μs = 0.59 . What is the maximum speed, in meters per second, he can travel through the arc without slipping?arrow_forwardYou have a grindstone (a disk) that is 397.84 kg, has a 0.272-m radius, and is turning at 30.804 rpm, and you press a steel axe against it with a radial force of 38.339 N. Assuming the kinetic coefficient of friction between steel and stone is 0.597. How many turns will the stone make before coming to rest? You have a grindstone (a disk) that is 397.84 kg, has a 0.272-m radius, and is turning at 30.804 rpm, and you press a steel axe against it with a radial force of 38.339 N. Assuming the kinetic coefficient of friction between steel and stone is 0.597. How many turns will the stone make before coming to rest?arrow_forward
- A gymnast does cartwheels along the floor and then launches herself into the air and executes several flips in a tuck while she is airborne. If her moment of inertia when executing the cartwheels is 13.5 kg · m2 and her spin rate is 0.5 rev/s, how many revolutions does she do in the air if her moment of inertia in the tuck is 3.4 kg · m2 and she has 2.0 s to do the flips in the air?arrow_forwardA common carnival ride, called a gravitron, is a large cylinder in which people stand against the wall of the ride as it rotates. At a certain point the floor of the cylinder lowers and the people are surprised that they don't slide down. Suppose the radius of the cylinder is r = 12 m, and the friction between the wall and their clothes is μ = 0.62. Consider the tangential speed v of the ride's occupants as the cylinder spins. a) What is the minimum speed, in meters per second, that the cylinder must make a person move at to ensure they will "stick" to the wall? Vmin = b) What is the frequency fin revolutions per minute of the carnival ride when it has reached the minimum speed to "stick" someone to the wall? f=arrow_forwardTerror Twins Steve and Phil are playing on a very large merry-go-round coated with ice (frictionless). mSteve =mPhil = 47.6 kg. The merry-go-round is spinning at a constant rate of revolution as the Terror Twins ride on it. Steve sitting 2.00 m from the center and must hold on to one of the metal posts with a horizontal force of 80.0 N to keep from sliding off. If Phil is sitting at the edge 4.00 m from the center, with what force must he hold on to keep from falling off?arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningUniversity Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice University