Two negative charges are separated by a distance d

Two negative charges are separated by a distance d

 

 

Two negative charges are separated by a distance d, as shown in the figure.

Which of the following statements is or are true?

i. The two charges are attracted to one another.

ii. The electrostatic potential energy of this system is positive.

iii. As d increases, the electrostatic potential energy decreases.

 

a. Only one of the statements is true.

b. i and ii are true.

c. i and iii are true.

d. ii and iii are true.

e. All three statements are true.

 

 

 

i. The two charges are attracted to one another.

> 같은 전하끼리는 반발한다. false

 

 

 

ii. The electrostatic potential energy of this system is positive.

> (–) × (–) = (+). true

 

[참고] If the two interacting charges are both positive or both negative, then the potential energy is positive.

 

 

 

iii. As d increases, the electrostatic potential energy decreases.

> 분모인 d가 증가하면, 에너지는 감소. true.

 

 

( 참고: Coulomb’s law https://ywpop.tistory.com/22358 )

 

 

 

답: d. ii and iii are true.

 

 

 

 

[참고] electrostatic potential energy (PE)

The potential energy depends on the sign of the charges and their separation.

( 참고 https://texasgateway.org/resource/184-electric-potential )

 

[1] 같은 전하끼리는

① d 증가하면, PE는 감소.

② d 감소하면, PE는 증가.

 

 

[2] 다른 전하끼리는

① d 증가하면, PE는 증가.

② d 감소하면, PE는 감소.

 

 

 

 

[ 관련 글 https://ywpop.tistory.com/11987 ]

이온 사이의 거리에 따른 에너지 변화

graph of potential energy versus internuclear distance

 

[ 관련 글 chem.libretexts.org ] Plot of potential energy versus internuclear distance for the interaction between ions with different charges

 

---> attractive interactions만 보자.

(+)입자와 (–)입자 사이의 거리가 감소하면,

potential energy도 감소한다.

 

 

 

[키워드] electrostatic potential energy 기준, 전기적 위치 에너지 기준, 정전기적 퍼텐셜 에너지 기준, electrostatic potential energy dic, 전기적 위치 에너지 사전, 정전기적 퍼텐셜 에너지 사전