A 1.5 kW motor is running at 1440 rev/min. Its is to be connected to a stirrer running at 36 rev/min. The gearing arrangement suitable for this application is

As shown in Figure, a mass of 100 kg is held between two springs. The natural frequency of vibration of the system, in cycles/s, is

Availability of a system at any given state is

A certain mass of a pure substance undergoes an irreversible process from state $$1$$ to state $$2,$$ the path of the process being a straight line on the $$T$$-$$s$$ diagram. Calculate heat transfer & work done. Some of the properties at the initial and final states are:
$${T_1} = 330\,K,\,\,{T_2} = 440\,K;\,\,{U_1} = 170\,kJ,\,\,$$
$$\,{U_2} = 190\,kJ;\,\,{H_1} = 220{\,_{}}kJ,\,\,{H_2} = 247\,kJ,$$
and $${S_1} = 0.23\,kJ/K$$ and $${S_2} = 0.3\,kJ/K$$ where $$T, U, H$$ and $$S$$ represent temperature, internal energy, enthalpy and entropy respectively.