# Homework Help: Simple work problem

1. Oct 18, 2007

### Laban

Hello :)
I must have missed something. This problem is extremely simple and yet I can't figure out what I'm doing wrong. Really frustrating!

The problem:
A bucket of mass 6.75 kg hangs in a well at the end of a rope. The rope passes over a frictionless pulley at the top of the well, and you pull horizontally on the end of the rope to raise the bucket slowly a distance of 4 m.

How much work do you do on the bucket in pulling it up?

My Guess
Since you need to raise the bucket, you need to pull with a force that equals the downwards gravitational force on the bucket. This is 6.75*9.8 = 66.15 N.
Now you pull it a distance of 4 m. This is 66.15*4 = 264.6 J.

But this is wrong! It's supposed to be 3.6 J

What am I supposed to do, and more importantly, why is what I'm doing wrong? This is supposed to be so simple >.<

2. Oct 18, 2007

### Staff: Mentor

It is simple and you're doing it correctly. That 3.6 J answer is bogus.

3. Oct 18, 2007

### Vijay Bhatnagar

You have solved the problem correctly. 3.6 J is incorrect.

4. Oct 18, 2007

### Laban

I sure hope you're both right. Thanks!