A piece of string is wound tightly around a cylinder for 20 complete turns. The length of the string is found to be 3.96cm. calculate the diameter of the cylinder in cm

2 answers

1 turn would be 3.96/20 cm = .195 cm
so πd = .195 , where d is the diameter
d = .195/π = ...

wow, that's some tiny cylinder
6.3