Minimum Length of Cuts for Unfolding Box Into Flat Sheet?

[Darkmisc]

Homework Statement

What is the minimum length of cuts necessary to make a net from a 10x5x3 box?

Relevant Equations

None.

Hi everyone

I got 36 cm as the answer for the following problem, but it's supposed to be 32cm.

These are the cuts I have
4 x 5cm = 20cm
2 x 3cm = 6 cm
1 x 10cm = 10cm
which adds up to 36cm.

I can get 32cm with
4x3=12
2x5=10
1x10=10

But I don't think that would be the correct net.

Is there a mistake in the answer?

Thanks

 

[Darkmisc]

Nevermind. I have the wrong net.

 

[Delta2]

It's not clear to me what you mean by "open the box to form a net"? How do you define the net? So that all vertices of the box lie on the same plane?

 

[Darkmisc]

I just needed to make cuts so that the box could be unfolded into a single, flat sheet. I made the cuts in the wrong place. That's why I got 36cm.

 

[Delta2]

I just needed to make cuts so that the box could be unfolded into a single, flat sheet. I made the cuts in the wrong place. That's why I got 36cm.

Ok fine , something else I didn't quite understand, every cut must be made along one of the 12 edges of the box or you can do "random diagonical" cuts?

 

[Darkmisc]

I think it's only along the edges.

 

[berkeman]

I just needed to make cuts so that the box could be unfolded into a single, flat sheet.

I was also confused by your original title mentioning "net". I've updated your title to make it more clear what you were trying to do.

 

[WWGD]

It reminds me of this episode of " Two and a Half Men", where Charlie calls a place asking for a net. They leave him waiting for a good 10 minutes, then this lady answers. Charlie asks: " Who are You"? She says " Annette ".

 

[WWGD]

Homework Statement:: What is the minimum length of cuts necessary to make a net from a 10x5x3 box?
Relevant Equations:: None.

Hi everyone

I got 36 cm as the answer for the following problem, but it's supposed to be 32cm.

View attachment 304291

These are the cuts I have
4 x 5cm = 20cm
2 x 3cm = 6 cm
1 x 10cm = 10cm
which adds up to 36cm.

View attachment 304290I can get 32cm with
4x3=12
2x5=10
1x10=10

But I don't think that would be the correct net.

Is there a mistake in the answer?

Thanks

Careful, though. By dimensional analysis, your units here are area ( squared) units, as they're all products of ( $cm )(cm)=cm^2$. You're removing rectangular sections, not linear ones, which I believe is what the problem asks you to do.

 

[DaveC426913]

I was also confused by your original title mentioning "net". I've updated your title to make it more clear what you were trying to do.

I remember when I first heard the word "net" applied to a 2D template for a 3D object.
I don't know if I just never learned that term in school, or if was introduced in the 21 century as part of the "new math".

 

[anuttarasammyak]

Homework Statement:: What is the minimum length of cuts necessary to make a net from a 10x5x3 box?
Relevant Equations:: None.

I can get 32cm with

32cm seems all right.