Question

two points b and c lie on radial line of a rotating disk. the points are 2 inches apart. vb=700 ft/min and vc=880 ft/min. find the radius of rotation for each of these points. slader

Answer 1

Let the radius be r

let us assume C is at the edge

so distance from center$= r ft$

B will then be = $(r - \frac{2}{12}) ft$

angular velocity will be same hence

$\frac{Vb}{Rb}= \frac{Vc}{Rc}$

$\frac{700}{(r - \frac{1}{6})} = \frac{880}{r}$

$\frac{r}{(r - \frac{1}{6})} = 1.257$

$r = 1.257r - 0.2095$

$0.257r = 0.2095$

$r = 0.815 ft$

Hence C is at 0.815 ft and B is at 0.648 ft