Atmospheric conditions near a rain forest are such that a cloud at an altitude of 1.60 km contains 3.20×10⁷ kg of water vapor. How long (in years) would it take for a 2.75 kW pump to raise this amount of water (at a constant speed) from Earth's surface to the altitude of the cloud?
An energy-efficient lightbulb, taking in 23.0 W of power, can produce the same level of brightness as a conventional lightbulb operating at power 100 W. The lifetime of the energy-efficient bulb is 10000 h and its purchase price is $4.70, whereas the conventional bulb has lifetime 750 h and costs $0.60 per bulb. Determine the total savings obtained by using one energy-efficient bulb over its lifetime as opposed to using conventional bulbs over the same time period. Assume an energy cost of $0.20 per hour. $