If hydrogen were used as a fuel, it could be burned according to the following reaction: h2(g) + 1/2o2(g) --> h2o(g) use average bond energies to calculate delta h rxn for this reaction and also for the combustion of methane (ch4). which fuel yields more energy per mole? per gram?

Acave rescue team lifts an injured spelunker directly upward and out of a sinkhole by means of a motor-driven cable. the lift is performed in three stages, each requiring a vertical distance of 11.0 m: (a) the initially stationary spelunker is accelerated to a speed of 4.80 m/s; (b) he is then lifted at the constant speed of 4.80 m/s; (c) finally he is decelerated to zero speed. how much work is done on the 78.0 kg rescue by the force lifting him during each stage

During takeoff, the sound intensity level of a jet engine is 170db at a distance of 34 m. what's the sound intensity level at a distance of 1.0 km?

A( developed during the process of technology design