A hoop and a disk both of radius Y roll, without slipping, down an inclined plane sitting on a table. The mass of the hoop is My and the mass of the disk ism & The height of the inclined plane above the table (as indicated in the figure) is h. The inclined plane makes an angle 0 with respect to the horizontal. Assume the table continues to the right, even though it does not in the figure. 13. What is the potential energy of the hoop at the top of the inclined plane? PEh = mn oh 14 . What is the potential energy of the disk at the top of the inclined plane? PEd = magh 15. What is the kinetic energy of the hoop at the bottom of the inclined plane? KEn = mugh- is h/sing (note the KE Is the sun of translational + rotational KE'S ) 16 . What is the kinetic energy of the disk at the bottom of the inclined plane? KEd = md 2 pts 1 7. What is the speed of the hoop at the bottom of the inclined plane? Vn = Jugh 18. What is the speed of the disk at the bottom of the inclined plane? 19. What is the angular momentum of the hoop at the bottom of the plane : in terms mu, her? 2 pts 20. What is the angular momentum of the disk at the bottom of the plane? in terms of my , his La = mar Jagh ) . We've said in class that angular momentum changes when a torque is applied to a system. Consider the hoop as the "system". What force produces the torque that creates the angular momentum? static frictionapts 22 . . How much work does the torque-producing force in (21) do as the hoop rolls from the top to the bottom? Wtorque = 5 msh ( noke Wtorque = OKEnot ) An 80 kg merry-go-round of radius 1.25 m is accelerated by wrapping a rope around it and pulling on it with a constant force of 25 N for 4.0 s, and then the rope is removed. The moment of inertia of a disk of mass M and radius R is = MR. What is the angular acceleration of the merry-go-round and how fast is it spinning (angular speed) after 4.0 s? 23. What is the angular acceleration of the MG-R after 45 ? dmar = 1.25 mad/ 2 24 . what is the angular speed of the M-GR after 45 2 w mar= a rally After the rope is removed, someone places a 10 kg block on the edge of the merry-go-round, which slows down the merry-go-round to 1.6 rad/s. The block does not slip due to static friction and rotates with the merry-go-round. 2pts 25 . What was the angular speed of the MG-R just before the block was placed on it ? Wmar = 1. 8 radlc ( use consun of ang. mom ) 26. The coefficient of static friction is 0.7 . what is the state friction force on the black? fe = 32N in the tangentid direction