Understanding Work: Calculating Work in Different Scenarios

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When holding a bag of groceries while standing still, no work is done because there is no movement, resulting in W=0. In contrast, when carrying the bag across a distance, the work done is calculated using the formula W=F·s, where F is the force and s is the distance. The discussion clarifies that gravitational work alone is not sufficient to answer the second question. Participants emphasize the importance of understanding the relationship between force and distance in calculating work. Ultimately, the correct approach to both scenarios involves recognizing that work is only done when there is movement in the direction of the applied force.
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Homework Statement


Here are two questions I have some trouble answering :
1- How much work do you do when you hold a bag of groceries while standing STILL?
2- How much work do you do when carrying the same bag on a distance d across the parking lot of the grocery store?

Homework Equations



We know that ΔK = W

The Attempt at a Solution


1- In the first question , the person stand still so V = 0 and thus ΔK=0 so the work W=0
2- In the second question, when carrying the bag we only have a gravitational work so W= Wg=0

IS IT CORRECT ?
 
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First question:
Yes you are right.There's another way to solve that.
##W=F.s## You are applying an equal and opposite force to that of gravity but it's not moving so ##W=F.0=0##

Second question:
I don't understand that W=Wg part.
The question asked how much work you do.
Use ##W=F.s## and answer!
 
what is F and s ??
 
physicos said:
what is F and s ??
"F" is the force and "s" is the distance in the direction of the force.
W is the work done.
 
Ah ok , I got it ! Thank you SO MUCH !
 
physicos said:
Ah ok , I got it ! Thank you SO MUCH !
So ... what is your answer http://physicsforums.bernhardtmediall.netdna-cdn.com/images/icons/icon5.gif
 
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