In 9.7 s a fisherman winds 2.1 m of fishing line onto a reel whose radius is 30 cm (assumed to be constant as an approximation).

The line is reeled in at constant speed.
Determine the angular speed of the reel in rad/s.
Thank you.

2 answers

The velocity of pulling in the line is is
V = w * R , which means
Linear speed = (Angular speed)*(Radius)
= 2.1m/9.7s = 0.2165 m/s

Angular speed = 0.2165/0.3
= 0.7216 rad/s
r = .30 meters
2 pi r = 1.88 m

2.1/1.88 = 1.11 revolutions

1.11 * 2 pi = 7 radians

7 radians / 9.7 s = .722 rad/s