Question

A roller has a diameter of 1.4 m. Find:

(i) Its circumference

(ii) The number of revolutions it makes while travelling 61.6 m.

Answer 1

Diameter =1.4 m

$r=\frac{1.4}{2}=0.7m$

$\therefore$ Circumference of roller $=2\pi r$

$=2\times \frac{22}{7}\times 0.7=4.4m$

Revolutions made in 4.4 m distance =1

Revolutions made in 1 m distance $=\frac{1}{4.4}$

Revolutions made in 61.6 m distance

$=\frac{1}{4.4}\times 61.6=\frac{616}{44}=14$

Hence (i)4.4 m(ii)14