Solving for Max Compression: 0.2kg Spring

[astrololo]

Homework Statement

A bloc of 0,2 kg is attached to a spring on a horizontal surface with no friction. (The other side of the spring is attached to a wall, so it doesn't move) The spring constant is 5 N/m. If we pull on the spring, we move it by 0,12 m from its natural position and we let it go after that (It has an initial speed of 0 m/s) What is the speed when we have a maximal compression

Homework Equations

U=1/2*k*e^2
Kf+Uf=Ki+Ui

The Attempt at a Solution

I get the following equation : 0,2v^2 + 5e^2 = 0,072

I don't know what is the maximal compression !

 

[gneill]

Homework Statement

A bloc of 0,2 kg is attached to a spring on a horizontal surface with no friction. (The other side of the spring is attached to a wall, so it doesn't move) The spring constant is 5 N/m. If we pull on the spring, we move it by 0,12 m from its natural position and we let it go after that (It has an initial speed of 0 m/s) What is the speed when we have a maximal compression

Homework Equations

U=1/2*k*e^2
Kf+Uf=Ki+Ui

The Attempt at a Solution

I get the following equation : 0,2v^2 + 5e^2 = 0,072

I don't know what is the maximal compression !

If the compression is maximal, how much more compression can there be?

 

[astrololo]

If the compression is maximal, how much more compression can there be?

Well 0...

 

[gneill]

Well 0...

Right. So in that instant, what is the block doing? Can it continue to move to compress the spring?

 

[astrololo]

Right. So in that instant, what is the block doing? Can it continue to move to compress the spring?

At that moment, the spring is pushing against the bloc to the right. I just don't know what is the position at the maximum. I know tha tmy natural position is 0.

 

[gneill]

At that moment, the spring is pushing against the bloc to the right.

Yes, but what is the block doing in that instant?

 

[astrololo]

Yes, but what is the block doing in that instant?

Ehhhhh... I think it has something do with speed ?

 

[gneill]

Ehhhhh... I think it has something do with speed ?

Yes. Think it through. The block moves, compressing the spring until it can't compress it any further. That's maximal compression. So the block's speed at that instant is...?

 

[astrololo]

Yes. Think it through. The block moves, compressing the spring until it can't compress it any further. That's maximal compression. So the block's speed at that instant is...?

It's 0 ? But I don't understand why...

 

[gneill]

It's 0 ? But I don't understand why...

Okay, here's an analogy. You throw a ball straight up in the air. What is the speed of the ball when it reaches is maximal height?

 

[astrololo]

Okay, here's an analogy. You throw a ball straight up in the air. What is the speed of the ball when it reaches is maximal height?

Its gooing to be 0 because the ball needs negative speed to go down.

 

[gneill]

So when the block reaches the maximal compression of the spring...

 

[astrololo]

So when the block reaches the maximal compression of the spring...

OH LOL ! WHen its at the maximum it doesn't move anymore ! I guess that me and my brain who are tired today ! thank you!