Example $1.$ The tworking conditions to be satisfied by a shaft transmitting

power are $($a$)$ that the shaft must not twist more than $1$ degree on a length of

$15$ diameters, and $($b$)$ the shear stress must not exceed $55\frac{N}{m}{m}^2.$

If $G=80,000\frac{N}{m}{m}^2$ what is the actual working stress, and the dia$-$

meter of shaft to transmit $1$ MW at $240$ r$.$p$.$m$.?$

Calculate the torque which can be transmitted for a given diameter

according to the two conditions.