Acompound gearbox is to be designed as part of a lifting hoist. the hoist shaft must operate at 20 r. p.m. the gearbox will be driven by a motor of output power 1.2kw. the output torque from the motor is 8nm. within the gearbox, the maximum speed ratio to be used at any stage is 3: 1. the minimum number of teeth on any gear pair is 18. determine: (i)theoretical gearbox ratio (ii)number of gearbox stages needed (iii)number of teeth on all gears (iv)actual speed ratio at each stage (v)actual output torque

The y form of iron is known as: a) ferrite b) cementite c) perlite d) austenite

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.

Consider a large isothermal enclosure that is maintained at a uniform temperature of 2000 k. calculate the emissive power of the radiation that emerges from a small aperture on the enclosure surface. what is the wavelength ? , below which 10% of the emission is concentrated? what is the wavelength ? 2 above which 10% of the emission is concentrated? determine the wavelength at which maximum spectral emissive power occurs. what is the irradiation incident on a small object placed inside the enclosure?