In a charming 19th-century hotel, an old-style elevator is connected to a counterweight by a cable that passes over a rotating disk 2.00 m in diameter (the figure ). The elevator is raised and lowered by turning the disk, and the cable does not slip on the rim of the disk but turns with it.
To start the elevator moving, it must be accelerated at {textstyle{1 over 8}},g. What must be the angular acceleration of the disk, in {rm{rad/s}}^2?