- #1
Laban
- 10
- 0
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 >.<
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 >.<