- Thread starter
- #1

#### karush

##### Well-known member

- Jan 31, 2012

- 2,928

it takes $18\text { s}$ for $56\text { cm}$ of belt to go around the pulley.

(a) find the angular speed of the pulley in $\displaystyle\frac{\text {rad}}{\text{s}}$

well from $\displaystyle\frac{56\text { cm}}{18\text{ s}}

\approx \frac{3.11\text { cm}}{\text{s}}$

and $\displaystyle\text {rad}=\frac{S}{r}

=\frac{3.11\text { cm}}{12.96\text { cm}}

\approx 0.34 \text{ rad}$

since $\text{S}$ is the arc length for one $\text{s}$ then

$\displaystyle\approx \frac{0.34\text {rad}}{\text{s}}$ angular speed

(b) find the linear speed of the belt in $\displaystyle\frac{\text {cm}}{\text{s}}

\approx \frac{3.11\text { cm}}{\text{s}}$

well if correct?? it seem a little bit choppy way to solve it.