P. 4016. The axle of a pulley of mass m=1 kg is attached to the end of a spring of spring constant D=200 N/m whose other end is fixed to the ceiling. A rope of negligible mass is placed to the pulley such that its left end is fixed to the ground and its right end is hanging freely from the pulley. At one moment we begin to pull the endpoint A at the right end of the rope by a constant vertical force of F=15 N. Friction can be neglected between the rope and the pulley.
a) What is the initial elongation of the spring?
b) Find the greatest elongation of the spring.
c) Find the maximum displacement of point A.
Deadline expired on 11 December 2007.