Work done lifting and sliding a box with friction

[MisterP]

Homework Statement

To lift a box it needs 250N force (F). How much work (A) has to be done to lift it at height (h) 1.2m and to slide it horizontaly (l) 1.2m. Coefficient of friction is 0.2 (μ)
F = 250N
h = 1.2m
l = 1.2m
μ = 0.2
A = ? on both situations
2. Homework Equations
A = F * h
A = F * l * μ

The Attempt at a Solution

A (when box has to be lifted) = 250 * 1.2 = 300 J (Joules)
A(when box has to be slided) = 250 * 1.2 * 0.2 = 60J

Is this right?

 

[BvU]

Any doubts ?

 

[MisterP]

I have the right answers and I just made these formulas up to get to answers, that's why I am asking. Answers are given. :)

 

[BvU]

thats why I am asking

And I was asking if you have any doubts. Do you ?

 

[sojsail]

Where you said "I just made these formulas up", do you mean that since you knew what the right answer was, you played with the data until you found what combination of operations with them would yield that answer? If I assume the answer to that is yes, then I assume your need is to understand how and why that worked.
For a discussion of what your formula A = F * h did, go to the website http://www.softschools.com/formulas/physics/work_formula/84/
Your A = F * l * μ worked, but the order in which you wrote the 3 parameters suggests lack of understanding.
For a discussion of how to calculate the force required to overcome friction, go to http://www.softschools.com/formulas/physics/friction_formula/32/

I hope this helps.
Or, you may reply to my reply if you would like to get further help toward better understanding.