Question

if a 21 inches diameter pulley that is being driven by an electric motor abd running at 1600 revolution per minutes is connected by belt to a 5 inch diameter pulley to drive a saw. what is the speed of the saw in revolution per minutes?

Answer 1

Speed of the saw may be calculated using the formula:

$$v_1 = \frac{d_1}{d_2} v_2$$

In our case $d_1 = 21$; $d_2 = 5$; $v_2 = 1600$. Substituting these values to the formula we get:

$$v_1 = \frac{21}{5} \cdot 1600 = 6720$$

So the speed of the saw equals to 6720 revolution per minute.

**ANSWER**: 6720 revolution per minute.