Question

A wheel of perimeter 220 cm rolls on a level road at a
speed of 9 km/h. How many revolutions does the wheel
make per second ?
​

Answer 1

Answer:

Let, its angular speed is

$\alpha$

about the centre and the linear speed v of tje centre are related as,

$v = \alpha r$

$= > \alpha = \frac{v}{r} = \frac{9}{220}$

$= > \frac{2\pi \times 9 \times {10}^{5} }{220 \times 3600}$

$= > \frac{900}{22 \times 36}$

$= > \frac{25}{22}$

Answer 2

Explanation:

Let, its angular speed is

\alphaα

about the centre and the linear speed v of tje centre are related as,

v = \alpha rv=αr

= > \alpha = \frac{v}{r} = \frac{9}{220}=>α=rv=2209

= > \frac{2\pi \times 9 \times {10}^{5} }{220 \times 3600}=>220×36002π×9×105

= > \frac{900}{22 \times 36}=>22×36900

= > \frac{25}{22}=>2225