A concentrated mass $$m$$ is attached at the centre of a rod of length $$2L$$ as shown in the figure. The rod is kept in a horizontal equilibrium position by a spring of stiffness $$k.$$ For very small amplitude of vibration, neglecting the weights of the rod and spring, the un damped natural frequency of the system is

A circular solid disc of uniform thickness $$20mm,$$ radius $$200mm$$ and $$mass$$ $$20kg,$$ is used as a fly wheel. If it rotates at $$600$$ $$rpm,$$ the kinetic energy of the flywheel, in joules is

An ideal gas of mass $$m$$ and temperature $${T_1}$$ undergoes a reversible isothermal process from an initial pressure $${P_1}$$ to final pressure $$P{}_2.$$ The heat loss during the process is $$Q$$. The entropy changes $$\Delta S$$ of the gas is

Air enters an adiabatic nozzle at $$300$$ $$kPa,$$ $$500$$ $$K$$ with a velocity of $$10$$ $$m/s.$$ It leaves the nozzle at $$100$$ $$kPa$$ with a velocity of $$180$$ $$m/s.$$ The inlet area is $$80$$ $$c{m^2}.$$ The specific heat of air $${C_p}$$ is $$1008$$ $$J/kg.K.$$

The exit temperature of the air is