Question

A cylinder of circumference 8 cm and length 21 cm rolls without sliding for $4\frac{1}{2}$ seconds at the rate of 9 complete rounds per second.Find the Distance travelled by the cylinder in $4\frac{1}{2}$ seconds.

Answer 1

Cylinder rolls at the rate of $9$ round per second
So, total round in $4.5$ second $=9\times 4.5=40.5$ round
The distance travelled by the cylinder in $1$ round $=$ its circumference $=8cm$
$\therefore$ distance travelled by the cylinder in $4.5$ seconds $=40.5\times 8=324cm$