A roll of paper is rolled on the floor in such a way that it is leaving paper on the behind it as it rolls. The paper left behind remains stationary on the floor. The roll is given an initial velocity V= 7.5 m/s. The initial radius of the roll is R = 1 m. Find the velocity of the roll Vf in m/s, when the radius of the roll is r = 0.6 m. Assume the roll rolls without slipping and that gravity acts on the roll. Also assume that the mass distribution of the paper on the roll is homogeneous. (Take g = 10 m/s^2)

answer would be letter choice (a),   a ball resting on a shelf. would be another example of potential energy   >   stored energy > not moving.

a ball spinning on a finger   >   kinetic energy > moving energy

a ball rolling on the ground   >   kinetic energy   > moving energy

a   ball flying through the air   > kinetic energy   >   moving energy

hope that                                         : )

a.metals can become magnetic if they have many spinning electrons that create magnetic fields.d.only some metals are attracted by magnets; these metals are called ferromagnetic.

d.wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current.