Understanding Work: Calculating Work in Different Scenarios

[physicos]

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 ?

 

[adjacent]

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!

 

[physicos]

what is F and s ??

 

[adjacent]

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.

 

[physicos]

Ah ok , I got it ! Thank you SO MUCH !

 

[NascentOxygen]

Ah ok , I got it ! Thank you SO MUCH !

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