Sounds like 10.0 ft refers to the height/diameter of the wheel, in which case its radius is 5.0 ft.
In one complete revolution, a point on the edge of the wheel travels 2π*(5.0 ft) = 10π ft, so the point's linear speed (and thus the current's speed) is
(5.0 rev/min) * (10π ft/rev) = 50π ft/min
Convert this to mi/h using
1 mi = 5280 ft
1 h = 60 min
==> (50π ft/min) * (1/5280 mi/ft) * (60 min/hr) = 1.8 mi/h
Answer:
I remember my teacher saying that when you get the answer you have to * when you get the answer
The general term is obtained by starting with the initial value 5 and then subtracting 4 each time you wish to generate a new term:
a2 = second term = 5+(2-1)(-4) = 5+(-4) = 1
General term:
an = nth term = 5+(n-1)(-4)
Thus, the 21st term is 5+(21-1)(-4) = 5 + (20)(-4) = -75 (answer)