# Homework Help: Questions about Work

1. May 1, 2014

### physicos

1. The problem statement, all variables and given/known data
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?

2. Relevant equations

We know that ΔK = W

3. 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 ?

2. May 1, 2014

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!

3. May 1, 2014

### physicos

what is F and s ??

4. May 1, 2014

"F" is the force and "s" is the distance in the direction of the force.
W is the work done.

5. May 1, 2014

### physicos

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

6. May 2, 2014