Twice each year.
No. The sun is only ever overhead in places between the tropics of Cancer and Capricorn. Arkansas is further north than this.
In order for a Tropical Rain Forest to be considered a Tropical Rain Forest it must be located between the Tropic of Capricorn and the Tropic of Cancer.
No place will be over your head. Perhaps you mean 'where will the sun be overhead'. This is somewhere between the Tropics of Cancer and Capricorn, depending on the date.
Because of the sun being directly overhead.
They are called the middle latitudes, and include mostly regions with temperate climates.
The Tropic of Cancer is a line of latitude (23.5 o N) where the Sun is directly overhead at the Summer Solstice. The Tropic of Capricorn is a line of latitude (23.5 o S) where the Sun is directly overhead at the Winter Solstice.
The sun is directly overhead at noon.
The Tropic of Cancer is at approximately 23 degrees 30 minutes N latitude and marks the point on the Earth's surface where the Sun is directly overhead at the northern Summer Solstice. It also marks the northernmost point of the Tropic Zone. The Tropic of Capricorn is at approximately 23 degrees 30 minutes S latitude and marks the point on the Earth's surface where the Sun is directly overhead at the southern Summer Solstice. It also marks the southernmost point of the Tropic Zone.
In the tropics. The sun is straight overhead at some time or other, between the tropic of Cancer, in the north and the tropic of Capricorn. During the equinoxes (vernal and autumnal), the sun is directly overhead at the equator.
The Tropic of Cancer is the northernmost point where the Sun shines directly overhead at noon in the June solstice (summer), whereas the Tropic of Capricorn is the southernmost point where the Sun shines directly overhead at noon in the December solstice (winter).
They are respectively the most northern (Cancer) and the most southern (Capricorn) latitude on the Earth at which the Sun - once a year - may appear directly overhead at its culmination.
Directly between the Tropic of Cancer and the Tropic of Capricorn is the equator.