Here is a simple example. The inhabitants of a small island begin exporting beautiful cloth made from a rare plant that grows only on their island. Seeing how popular the small quantity that they export has been, they steadily raise their prices. A clothing maker from New York, thinking that he can save money by "cutting out the middleman," decides to travel to the small island and buy the cloth himself. Ignorant of the local custom of offering strangers outrageous prices and then negotiating down, the clothing maker accepts (much to everyone's surpise) the initial price of 400 . The price of this cloth in New York is 120 .
If the clothing maker bought 500 of this fabric, how much money did he lose? Use and .
Express your answer in dollars to three significant figures
Still think that unit conversion isn't important?
Here is a widely publicized, true story about how failing to convert units resulted in a huge loss. In 1998, the Mars Climate Orbiter probe crashed into the surface of Mars, instead of entering orbit. The resulting inquiry revealed that NASA navigators had been making minor course corrections in SI units, whereas the software written by the probe's makers implicitly used British units. In the United States, most scientists use SI units, whereas most engineers use the British, or Imperial, system of units. (Interestingly, British units are not used in Britain.) For these two groups to be able to communicate to one another, unit conversions are necessary.
The unit of force in the SI system is the newton ( ), which is defined in terms of basic SI units as . The unit of force in the British system is the pound ( ), which is defined in terms of the slug (British unit of mass), foot ( ), and second ( ) as .
Find the value of 15.0 in pounds. Use the conversions and .
Express your answer in pounds to three significant figures.