# Homework Help: Newton's 2nd

1. Sep 27, 2010

### daltomagne

A woman raises herself in a bucket. How hard must she pull downward to raise herself slowly at constant speed? The mass of the person plus the bucket is 79 kg.

m=79kg
g=9.8m/s^2 (downward)

i know $$\Sigma$$F=ma so i end up with 774.2 N. i'm a little lost as where to go now.

2. Sep 28, 2010

### fizzynoob

Sum the forces in the y direction, if speed is constant that acceleration is zero

Forces in y =Fp- Fg = 0

Solve for fp

3. Sep 28, 2010

### Olly4

You actually already solved it. For something to move at a constant speed, the net force has to be 0. So she just has to pull hard enough to overcome the gravitational force. Which you already calculated.

4. Sep 28, 2010

### Staff: Mentor

You need to understand how she is raising herself. A simple rope and pulley arrangement? A diagram would be helpful.