Which statement best describes a hydrogen fuel cell? ОА. .
This device uses bioethanol as an additive to power an automobile.
OB. This device uses photovoltaic cells to capture solar energy and generate electrical energy from it.
OC. This device uses fossil fuels to generate heat energy that machines can then convert into mechanical energy.
OD. This device converts the chemical energy of hydrogen into electricity through a chemical reaction with oxygen or another
oxidizing agent.
OE. This device converts the kinetic energy of an electric turbine into electricity based on Faraday's law.
Reset
Next

For a gate width of 2 m into the paper, determine the force required to hold the gate abc at its location.

An external consultant recommends that a plant installs a bank of capacitors for power factor correction. this will reduce the peak electrical demand charges by an average of 93 kw every month. the plant current pays $13 per kw in peak demand charges. the capacitor bank will include 223 kw of fixed capacitors, and 183 of variable capacitors. the fixed capacitors cost $59 per kw, and the variable capacitors will cost $65 per kw. the consultant charges 21% of the equipment costs to install the capacitors. because this project will reduce the demand for the electric utility, they are prepared to provide a one-time rebate of $42 per kw of reduced demand. what is the simple payback period for this project (in years)?

To design a steam turbine to produce 12,000 hp power. a engineer comsiders using a steady state stean low st 1160fr and engineer considers using a steady state steam flow at 1160°r and 450 psia to drive this steam turbine. the exhaust of the steam is cooled by the lake (vacuum). heat losing to the surroundings is measured at a rate of 555.55 btu/s. (a) sketch the system with the given conditions. (b) neglecting kinetic and potential energy changes from inlet to exit, determine the volumetric flow rate of the steam at the inlet, (ft'/hr). must clearly show unit conversions at crtical terms.