Regina has a shelf that is eight feet off the ground. When she was younger she used the shelf for storage, and her mom would help her use a ladder to reach things on it occasionally. Now she wants to use the shelf to hold her textbooks that she needs to use every day. She needs to be able to do this by herself without using the ladder. Regina needs to design a tool to help her reach the books ont he shelf easily and safely. She wants to use materials she finds around the house to make the tool. List one criterion and one constraint for the tool she is designing.

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explanation:

most historians agree that gabriel mouton, the vicar of st. paul’s church in lyons, france, is the “founding father” of the metric system. he proposed a decimal system of measurement in 1670. mouton based it on the length of one minute of arc of a great circle of the earth (now called a nautical mile, 1852 meters). he also proposed the swing-length of a pendulum with a frequency of one beat per second as the unit of length (about 25 cm). a pendulum beating with this length would have been fairly easy to produce, thus facilitating the widespread distribution of uniform standards. over the years, his work was revised, improved, and extended by a number of french scientists.

the political sponsor of weights and measures reform in the french revolutionary national assembly was the bishop of autun, better known as talleyrand. under his auspices, the french academy appointed several committees to carry out the work of developing a usable system of weights and measures for france. one of the committees recommended a decimalized measurement system based upon a length equal to one ten-millionth of the length of a quadrant of the earth’s meridian (i.e., one ten-millionth of the distance between the equator and the north pole).