Why is W Tot not equal to W Glider on Spring in Newton's Third Law?

[Selfless_Gene]

Homework Statement

Hello I am solving a problem that requires me to find the max distance of a glider with spring attached to it. I am getting confused on Work total, in an example in my textbook W total is the W friction + W spring on glider = W total. My question is why did the textbook example not include W glider on spring. I know these are action reaction pairs from Newtons third law, but is this valid to say W tot is only equal to W friction + W spring?

Thank You

Homework Equations

W tot = K2 - K1

The Attempt at a Solution

 

[haruspex]

Homework Statement

Hello I am solving a problem that requires me to find the max distance of a glider with spring attached to it. I am getting confused on Work total, in an example in my textbook W total is the W friction + W spring on glider = W total. My question is why did the textbook example not include W glider on spring. I know these are action reaction pairs from Newtons third law, but is this valid to say W tot is only equal to W friction + W spring?

Thank You

Homework Equations

W tot = K2 - K1

The Attempt at a Solution

You need to be clear what total is being considered. Total work done by what, or done on what?
"W friction + W spring on glider" suggests you want the total work done by the spring, and that this includes some work done against friction whilst accelerating the glider. Is that right?
Work done by the glider on the spring is equal and opposite to that done by the spring on the glider, so if you add them they will cancel out.

 

[Selfless_Gene]

You need to be clear what total is being considered. Total work done by what, or done on what?
"W friction + W spring on glider" suggests you want the total work done by the spring, and that this includes some work done against friction whilst accelerating the glider. Is that right?
Work done by the glider on the spring is equal and opposite to that done by the spring on the glider, so if you add them they will cancel out.

When I refer to total work my textbook has a formula and which is W tot = K2-K1. So to be more clear my question is in order to use this formula do we have to consider all the work done in this system by all forces? I ask this because in the example they used W tot = W fric + W spring on glider . It did not include W glider on spring.

Thank You

 

[haruspex]

my textbook has a formula and which is W tot = K2-K1

That appears to be expressing the increase in KE. That would be right if it means the total work done on a mass.
If the mass is a glider being accelerated by a spring that encounters friction, it would equal "W spring on glider". It would not include the work done by the spring against friction.

in the example they used W tot = W fric + W spring on glider

That would be right for the total work done by the spring. It would not equal K2-K1.
Now, I don't know where exactly this friction acts during acceleration. Maybe some acts directly on the spring while other friction acts on the glider:

Total work done by spring
    ├→ Work done by spring against friction during acceleration
    ↓
Work done by spring on glider
    ├→ Work done by glider against friction during acceleration
    ↓
Total work done on glider
    =  increase in glider KE

Could you post the section of the textbook, maybe as an image?