A polyamide conveyor belt is required to transport crushed rocks at a distance of 10 ft at a speed of 3 ft/sec. The maximum weight of the cruched rock on the belt is 150 lb and the coefficient of static friction between the belt and the rock is 0.12. Design a flat belt drive. Assume a gearbox reduces the speed from a 10-hp electric motor running at 1750 rpm to the belt drive.

The force on a cutting tool are 2600n vertically downward and 2100 horizontal. determine the resultant force acting on the tool and the angle at which it acts.

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.