# Fish pulling on reel

1. Nov 7, 2009

### premedonna89

1. The problem statement, all variables and given/known data

A fish takes the bait and pulls on the line with a force of 1.8 N. The fishing reel, which rotates counterclockwise without friction, is a solid cylinder of radius 0.064 m and mass 0.80 kg.

(a) What is the angular acceleration vector of the fishing reel?

(b) How much line does the fish pull from the reel in 0.17 s?
m

2. Relevant equations

Torque = Inertia x angular acceleration
Inertia = 1/2 x Mass x Radius^2 (for solid cylinders/discs)
Angular Acceleration = acceleration/radius (I personally didn't think this was necessary, but then again I didn't get the right answer)

3. The attempt at a solution

I simply calculated Inertia by:

1/2 x 0.8 kg x (0.064 m)^2 = 1.6384 x 10^-3

Then I tried to calculate angular acceleration by:

1.8 N / (1.6384 x 10^-3) = 1098.63 rad/sec ^2

I was told by WebAssign that this was incorrect...so I entered it as a negative value (-1098.63) in case I was confused regarding the counterclockwise direction of the reel, but this was also considered incorrect.

I have not attempted part B yet because my approach for part B would involve knowing the angular acceleration.

2. Nov 7, 2009

### rl.bhat

Hi premedonna89, welcome to PF.
I*α = Torque = F*r.
Try this one.

3. Nov 7, 2009

### premedonna89

ah!

Torque = 1.8 x 0.064

*blush*

thank you!