$6\mathrm{.}2.$ The torque exerted on the crankshaft of an engine is given by the equation:

$T=15+2\mathrm{.}2sin2-1\mathrm{.}85cos2t,KN.m.$

where $$ is the crank angle displacement from the inner dead center. Assuming the resisting

torque to be constant, determine:

a$)$ The horsepower of the engine when the speed is $150rpm.$

b$)$ The moment of inertia of the flywheel if the speed variation is not to exceed $0\mathrm{.}5\%$ of the mean

speed.

c$)$ The angular acceleration of the flywheel when the crank has turned through $30$ degrees form

the I.D$.$C$.$