Edits to “Statement”, “Solution”, “Answer”
en/6.5.24.md
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| ### Statement | |||
| − | $6.5.24.$ [Insert the problem statement] | ||
| + | $6.5.24.$ A uniformly charged sheet having the shape of an isosceles right triangle was folded in half. In this case, work $A$ was performed against the forces of the electric field. What kind of work do you need to do to fold the resulting triangle again in the same way? | ||
| ### Solution | |||
| − | By folding an isosceles right triangle in half, its new linear dimension is $1/\sqrt2$ of its original dimension. If the electrical potential energy of the original charged triangle is $U$, then the potential energy of the new triangle is $\sqrt2U$, because potential energy varies inversely with distance | ||
| + | By folding an isosceles right triangle in half, its new linear dimension is $1/\sqrt2$ of its original dimension. If the electrical potential energy of the original charged triangle is $U$, then the potential energy of the new triangle is $\sqrt2\,U$, because potential energy varies inversely with distance between charges while total charges remain the same. Thus, the work done in the first folding is $A=\sqrt2\,U-U$. If the new triangle is folded once more, then the potential energy of the last triangle is $(\sqrt2)^2\,U$, and the work done in the second folding is $(\sqrt2)^2\,U-\sqrt2\,U=\sqrt2A$. | ||
| #### Answer | |||
| − | [Insert a concise answer or boxed result] | ||
| + | $\sqrt2A$ | ||
| @@ -1,11 +1,11 @@ | |||
| ### Statement | ### Statement | ||
| $6.5.24.$ [Insert the problem statement] | $6.5.24.$ A uniformly charged sheet having the shape of an isosceles right triangle was folded in half. In this case, work $A$ was performed against the forces of the electric field. What kind of work do you need to do to fold the resulting triangle again in the same way? | ||
| ### Solution | ### Solution | ||
| By folding an isosceles right triangle in half, its new linear dimension is $1/\sqrt2$ of its original dimension. If the electrical potential energy of the original charged triangle is $U$, then the potential energy of the new triangle is $\sqrt2U$, because potential energy varies inversely with distance |
By folding an isosceles right triangle in half, its new linear dimension is $1/\sqrt2$ of its original dimension. If the electrical potential energy of the original charged triangle is $U$, then the potential energy of the new triangle is $\sqrt2\,U$, because potential energy varies inversely with distance between charges while total charges remain the same. Thus, the work done in the first folding is $A=\sqrt2\,U-U$. If the new triangle is folded once more, then the potential energy of the last triangle is $(\sqrt2)^2\,U$, and the work done in the second folding is $(\sqrt2)^2\,U-\sqrt2\,U=\sqrt2A$. | ||
| #### Answer | #### Answer | ||
| [Insert a concise answer or boxed result] | $\sqrt2A$ | ||