Question

A string trimmer is a tool for cutting grass and weeds; it utilizes a length of nylon "string" that rotates about an axis perpendicular to one end of the string. The string rotates at an angular speed of 45 rev/s, and its tip has a tangential speed of 63 m/s. What is the length of the rotating string?

Answer 1

Answer:

r = 22.3 cm

Explanation:

given,

angular speed = 45 rev/s

tangential speed  = 63 m/s

length of the rotating string

angular velocity =

ω = 2 π N

ω = 2 π x 45

ω = 282.74 rad/s

we know,

v = r ω

$r = \dfrac{v}{\omega}$

$r = \dfrac{63}{282.74}$

$r =0.223\ m$

r = 22.3 cm