Question

Each wheel on Harley's bike has a radius of 60 cm. How many revolutions does each bike make when Harley bikes 500 cm?
A. 500/120pi
B. 1000/120pi
C. 50000/120pi
D. 100000/120pi

Answer 1

well, the circumference is C = 2πr = 120π

so, the revolutions in 500cm can be found using

500cm * 1rev/120πcm = 500/120π rev = (A)

Who wants to ride only 5 meters? sheesh!

Answer 2

x = total turns
c = πd
60 cm = 0.6 m
since the radius 0.6 m, the diameter is 1.2.

turns * circumference = revolutions
that becomes:
x * 1.2π=500
solve it yourself, but it becomes x = 1250/3π

since all the denominators have 120π we can do proportions

1250/3π = y/120π

(y is another random variable)
solve the proportion your own
y =50000
that becomes 50000/120π, so your answer is c

Answer 3

Hey R, I think you meant total turns * circumference = total distance