Question 4
a drum a of mass 200 kg, external diameter 380 mm and radius of gyration 150 mm, rotates
on frictionless bearings at 250 rev/min. a stationary drum b of mass 50 kg, external diameter
and radius of gyration 80 mm, mounted on a frictionless axis parallel to that of a is pressed into
contact with a with a force of 90 n. the coefficient of friction is 0.25. determine the time
of slipping and the final speed of a and b (ii) the time of slipping it a torque is applied on a to
maintain constant speed of 250 rev/min.
question 5
() a homogeneous cylinder(radius = 650 mm) having a mass of 15 kg has a narrow peripheral
slot cut in it at radius, 450 mm as shown in fig. q5a. a force of 80 n is exerted on a string
wrapped in the slot. the cylinder rolls without slipping. determine the frictional force, f
and the angular velocity of the cylinder after 2 s.