An ad for an above-ground pool states that it has an area of 25 m2. from the photograph in the ad you can tell that the pool is circlular. if you swim from one point at the edge of the pool to another, along a straight line, what is the longest distance d you can swim

5.64 m

The longest straight line i.e. chord that can be drawn in a circle is its along the diameter.

we know area of a circle is given by:

Hence, the swimmer can swim the longest distance of d = 5.64 m in the pool.

an ion is a charged atom or molecule. it is charged because the number of electrons do not equal the number of protons in the atom or molecule. an atom can acquire a positive charge or a negative charge depending on whether the number of electrons in an atom is greater or less then the number of protons in the atom.