P. 4438. A uniform solid disc of mass m=5 kg, and of radius R=10 cm is rotated at an angular speed of 0=120 1/s about its symmetry axis, which is horizontal, and then it is carefully placed to the horizontal ground, such that it has no initial speed. The coefficient of friction between the disc and the ground is =0.4.
Determine the work done by the frictional force on the disc, while the disc covers a distance of s=5 m. Show that the result is the same if the work-kinetic energy theorem is used or if the product of the force and the displacement is calculated.
Deadline expired on 10 May 2012.