Calculating Force Needed to Lift 79kg Mass at Const. Speed

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Homework Help Overview

The problem involves calculating the force required for a woman to lift herself in a bucket at a constant speed, with a total mass of 79 kg. The context includes considerations of gravitational force and the dynamics of the system.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the application of force equations and the implications of constant speed on net force. Questions arise regarding the method of lifting and the setup of the system, including the need for a diagram.

Discussion Status

The discussion is active, with some participants providing guidance on the relationship between forces and acceleration. There is an exploration of different interpretations of the lifting mechanism, and no consensus has been reached regarding the specifics of the setup.

Contextual Notes

Participants note the importance of understanding the physical arrangement of the lifting mechanism, suggesting that additional information or a diagram could clarify the situation.

daltomagne
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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 [tex]\Sigma[/tex]F=ma so i end up with 774.2 N. I'm a little lost as where to go now.
 
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Sum the forces in the y direction, if speed is constant that acceleration is zero

Forces in y =Fp- Fg = 0

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

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