One alternative energy source is the temperature difference between surface and deep water in the tropical oceans. Suppose a heat engine uses $25^{\circ} \mathrm{C}$ surface water as its hot reservoir and $4^{\circ} \mathrm{C}$ deep water as its cold reservoir. (a) Find the maximum efficiency of such an engine.

An automobile engine with an efficiency $0.21$ dumps heat to the environment at the rate of $330 \mathrm{~kW}$. What's its mechanical power output, in W and in hp?

Most medium-and deep-focus earthquakes occur at ______.

Which single source of freshwater represents the largest volume of freshwater worldwide readily available for use by humans?

A. ice caps and glaciers

B. freshwater lakes

C. rivers and streams

D. groundwater deposits

What type of eruption formed this unit composed of volcanic blocks and volcanic ash?

A. a fluid basaltic flow

B. a pyroclastic eruption

C. a pahoehoe lava flow

D. a lava fountain

Each second a nuclear power plant extracts $1700 \mathrm{MJ}$ of thermal energy from its uranium fuel and dumps $1100 \mathrm{MJ}$ of waste heat into a river. (b) At what rate does it produce electrical energy, assuming all the work it does ends up as electricity?

Each second a nuclear power plant extracts $1700 \mathrm{MJ}$ of thermal energy from its uranium fuel and dumps $1100 \mathrm{MJ}$ of waste heat into a river. (a) What's its efficiency?

A $40 \%$ efficient heat engine does mechanical work at the rate of $400 \mathrm{~W}$. If it runs for an entire day, find the heat removed from the hot reservoir and the heat transferred to the cold reservoir.

A heat engine does $650 \mathrm{~J}$ of work and dumps $1270 \mathrm{~J}$ of heat to its cold reservoir. What's its efficiency?

Earth receives energy from the Sun at an average rate of about $240 \mathrm{~W} / \mathrm{m}^2$. Given Earth's average temperature of $15^{\circ} \mathrm{C}$, find the rate of entropy increase associated with this energy flow.

Find the entropy increase when $100 \mathrm{~g}$ of nitrogen boil at atmospheric pressure.

Using data from Chapter 13 , find the entropy increase in $1.5 \mathrm{~kg}$ of mercury when it melts at $-39^{\circ} \mathrm{C}$ and 1 atm pressure.

After Congress held hearings on violent content in television programming in 1993, cable operators and network broadcasters agreed that?

$150 \mathrm{~g}$ of water at $0^{\circ} \mathrm{C}$ are placed in a freezer at $-4^{\circ} \mathrm{C}$. Find the net entropy change after all the water has turned to ice but is still at $0^{\circ} \mathrm{C}$.