Question No$.12$: A belt drive is required to transmit $10$ kW from a motor running at $"600$ rpm$.$ The belt is $12$ mm thick $-$and $-$has a mass density of $0\mathrm{.}001\frac{g}{m}{m}^3.$ Safe stress in the belt is not to exceed $2\mathrm{.}5\frac{N}{m}{m}^2.$ Diameter of the driving pulley is $250$ mm $,$ whereas the speed of the driven pulley is $220$ rpm $.$ The two shafts are $1\mathrm{.}25$ m apart. The coefficient of friction is $0\mathrm{.}25.$ Determine the width of the belt.