# Homework Help: Rotation and power problem, help!

1. May 9, 2004

### Cyannaca

Hello, I would like it if anyone could help me with this problem

A bucket of 15 kg is lifted up from a well at a constant speed of 0,2 m/s. The cord rolls up around a winch (radius 0,03m). The winch is turned with a handle 0,4m of length
a) What power is necessary bring the bucket up?
b) If the force applied is always perpendicular to the handle, what is the module of the necessary force?

The answers are 29,4 W and 11 N and I don't know what is wrong but I always get 11,26 W

2. May 9, 2004

3. May 9, 2004

### Cyannaca

I finally solved a (afer half an hour!) but now I really don't know how to do b

4. May 9, 2004

### arildno

"module" means the same as "magnitude".
Does that help?

5. May 10, 2004

### enigma

Staff Emeritus
Welcome to the forums, Cyannaca!

Can you please post your calculations, so we can help find your error? Forum rules, plus it makes it much easier for everyone.

6. May 10, 2004

### Cyannaca

Ok, so I need to use Torque= radius*F* Thank you!