Distinguish between specific energy and energy density of a fuel.

A power plant operates in four stages. The efficiency in each stage is $80\% , 40\% , 12\%$ and $65\%$.

 Find the overall efficiency of the plant.

A power plant operates in four stages. The efficiency in each stage is $80\% , 40\% , 12\%$ and $65\%$.

Sketch a Sankey diagram for the energy flow in this plant

A coal power plant with $30\%$ efficiency burns $10 \mathrm{million} \mathrm{kg}$ of coal a day (take specific energy of coal to be $30 {\mathrm{MJkg}}^{-1}$)

Calculate the power output of the plant.

A coal power plant with $30\%$ efficiency burns $10 \mathrm{million} \mathrm{kg}$ of coal a day (take specific energy of coal to be $30 {\mathrm{MJkg}}^{-1}$)

Estimate the rate at which the thermal energy is discarded by this plant.

A coal power plant with $30\%$ efficiency burns $10 \mathrm{million} \mathrm{kg}$ of coal a day (take specific energy of coal to be $30 {\mathrm{MJkg}}^{-1}$)

Estimate the rate at which the thermal energy is discarded by this plant. The discarded thermal energy is carried away by water whose temperature is not allowed to increase by more than $5° \mathrm{C}$. Calculate the rate at which the water must flow away from the plant.

Heat capacity of water-$4200 \mathrm{J}$