Question

How many arcseconds are in one arcminute ?

Answer 1

The average apparent size of the full moon is roughly 31 arcminutes (or 0.52°). The human eye has a resolution of around one arcminute. At a distance of 4 kilometres, one arcsecond is roughly the angle subtended by a US dime coin (18 mm) (about 2.5 mi). At a distance of one astronomical unit, an arcsecond is the angle subtended by an object with a diameter of 725.27 km.

Complete answer:
A minute of arc, also known as an arcminute, arc minute, or minute arc, is a unit of angular measurement equal to $\dfrac{1}{{60}}$ of a degree, indicated by the sign '. One minute of arc equals $\dfrac{1}{{21600}}$ of a turn, since one degree equals $\dfrac{1}{{360}}$ of a turn.

The fact that "minute" and "second" also designate time units comes from Babylonian astronomy, when the equivalent time-related terminology represented the duration of the Sun's apparent motion across the ecliptic of one minute or one second of arc, respectively.The Babylonian degree of time was four minutes long in modern terms, therefore a "minute" of time was four seconds long and a "second" was one-fifteenth of a second.

Hence, an arcminute (abbreviated as ‘) is a unit of angular measurement equal to $\dfrac{1}{{60}}$ of a degree (60 arcseconds).

Note: Cartography and navigation also employ minutes (′) and seconds (′′) of arc. At sea level, one minute of arc along the equator equals exactly one geographical mile or about one nautical mile at the Earth's equator (1,852 metres; 1.151 miles). A second of arc is equal to one-sixtieth of this quantity, or around 30 metres (98 feet). Because the Earth's shape is somewhat oblate, the actual distance varies along meridian arcs or any other great circle arcs (bulges a third of a percent at the equator).