Pan Pearl River Delta Physics Olympiad 2023
2023年泛珠三角及中华名校物理奥林匹克邀请赛
Sponsored by Institute for Advanced Study,HKUST
香港科技大学高等研究院赞助
Simplified Chinese Part-2 (Total 2 Problems,60 Points)
简体版卷-2（共2题，60分)
(1:30pm-5:00pm,29 January2023)
All final answers should be written in the answer sheet.
所有最后答案要写在答题纸上。
All detailed answers should be written in the answer book.
所有详细答案要写在答题簿上。
There are 2 problems.Please answer each problem starting on a new page.
共有2题，每答1题，须采用新一页纸。
Please answer on each page using a single column.Do not use two columns on a single page.
每页纸请用单一直列的方式答题。不可以在一页纸上以双直列方式答题。
Please answer on only one page of each sheet.Do not use both pages of the same sheet.
每张纸单页作答。不可以双页作答。
Rough work can be written in the answer book.Please cross out the rough work after answering the questions.No
working sheets for rough work will be distributed.
草稿可以写在答题簿上，答题后要在草稿上划上交叉，不会另发草稿纸。
If the answer book is not enough for your work,you can raise your hand.Extra answer books will be provided.Your
name and examination number should be written on all answer books.
考试中答题簿不够可以举手要，所有答题簿都要写下姓名和考号。
At the end of the competition,please put the question paper and answer sheet inside the answer book.If you have
extra answer books,they should also be put inside the first answer book.
比赛结束时，请把考卷和答题纸夹在答题簿里面，如有额外的答题簿也要夹在第一本答题簿里面。Pan Pearl River Delta Physics Olympiad 2022
2023年泛珠三角及中华名校物理奥林匹克邀请赛
Sponsored by Institute for Advanced Study,HKUST
香港科技大学高等研究院赞助
Simplified Chinese Part--1(Total4 Problems,40 Points)简体版卷-1（共4题，40分）
(9:30am-12:00pm,29"Jan2023)
Please fill in your final answers to all problems on the answer sheet
请在答题纸上填上各题的最后答案。
At the end of the competition,please submit the answer sheet only.Question papers and working sheets will not be collected.
比赛结束时，请只交回答题纸，题目纸和草稿纸将不会收回。
1.[10 points]Consider a satellite that has a shape of a plate of surface
area A and thickness d
the temperature difference.The solar energy flux density [solar power
per unit area]at the position of the satellite is S and the satellite is
facing towards Sun.Assuming that the emissivity of both sides of the
satellite is e and the temperatures of the satellite on two sides are T
and T2 respectively and o is the Stefan-Boltzmann constant.
1.[10分]考虑一个人造卫星·其形状为表面积为A且厚度为d《
目
√A的平板。卫星可以利用温差将太阳能转化为电能·为星载电
池充电。人造卫星所在位置的太阳能通量密度[单位面积的太阳
能功率]为S，卫星正对着太阳。假设整颗卫星的发射率（又称辐
Surface area =A
射率)为e，卫星两侧的温度分别为T1和T2,o是Stefan--Boltzmann常数。
(a)[2]What is the net heat flux [energy per second]absorbed by the bright side (the side facing towards Sun)of the
satellite
()[2]卫星的亮面（面向太阳的一面）吸收的净热通量[每秒能量]是多少？
(b)[1]What is the net heat flux [energy per second]released from the dark side of the satellite
(b)[1]从卫星暗面释放的净热通量[每秒能量]是多少？
(c)[1]What is value of the emissivity e to get the theoretically maximal charging power Pnax
(c)[1]可得到理论上最大充电功率Pmax的发射率e的值是多少？
(d)[3]Find a condition for the temperature Ti in order to get the theoretically maximal charging power Pmax provided by
the satellite.Express the condition in term of the dimensionless variablexYou don't need to solve the equation
in this part.
(d[)求温度T的条件，使得卫星能潼到理论上最大充电功率乃max。用无量纲变量x=表示你的答案。你
不需要解这部分的方程·
(e)[3]What is the theoretically maximal charging power Pmax provided by the satellite Calculate the numerical value of
Your answer should be correct to at least 2 significant figures.
AS
(⊙)[3]卫星可提供的理论上最大充电功率Pmax是多少？计算mx的数值。你的答案至少应正确到2位有效数
AS
字。
12
Pan Pearl River Delta Physics Olympiad 2023
2023年泛珠三角及中华名校物理奥林匹克邀请赛
Sponsored by Institute for Advanced Study,HKUST
香港科技大学高等研究院赞助
Simplified Chinese Part-2 (Total 2 Problems,60 Points)
简体版卷-2（共2题，60分）
(1:30pm-5:00pm,29 January2023)
All final answers should be written in the answer sheet.
所有最后答案要写在答题纸上。
All detailed answers should be written in the answer book.
所有详细答案要写在答题簿上。
There are 2 problems.Please answer each problem starting on a new page.
共有2题，每答1题，须采用新一页纸。
Please answer on each page using a single column.Do not use two columns on a single page.
每页纸请用单一直列的方式答题。不可以在一页纸上以双直列方式答题。
Please answer on only one page of each sheet.Do not use both pages of the same sheet.
每张纸单页作答。不可以双页作答。
Rough work can be written in the answer book.Please cross out the rough work after answering the questions.No
working sheets for rough work will be distributed.
草稿可以写在答题簿上，答题后要在草稿上划上交叉，不会另发草稿纸。
If the answer book is not enough for your work,you can raise your hand.Extra answer books will be provided.Your
name and examination number should be written on all answer books.
考试中答题簿不够可以举手要，所有答题簿都要写下姓名和考号。
At the end of the competition,please put the question paper and answer sheet inside the answer book.If you have
extra answer books,they should also be put inside the first answer book.
比赛结束时，请把考卷和答题纸夹在答题簿里面，如有额外的答题簿也要夹在第一本答题簿里面。
11
Pan Pearl River Delta Physics Olympiad 2022
2023年泛珠三角及中华名校物理奥林匹克邀请赛
Sponsored by Institute for Advanced Study,HKUST
香港科技大学高等研究院赞助
Simplified Chinese Part--1(Total4 Problems,40 Points)简体版卷-1（共4题，40分）
(9:30am-12:00pm,29"Jan2023)
Please fill in your final answers to all problems on the answer sheet
请在答题纸上填上各题的最后答案。
At the end of the competition,please submit the answer sheet only.Question papers and working sheets will not be
collected.
比赛结束时，请只交回答题纸，题目纸和草稿纸将不会收回。
1.[10 points]Consider a satellite that has a shape of a plate of surface area A and thickness d
difference.The solar energy flux density [solar power per unit area]at the position of the satellite is S and the
satellite is facing towards Sun.Assuming that the emissivity of both sides of the satellite is e and the temperatures
of the satellite on two sides are Ti and T2 respectively and o is the Stefan-Boltzmann constant.
1.[10分]考虑一个人造卫星，其形状为表面积为A且厚度为d《VA的平板。卫星可以利用温差将太阳能
转化为电能，为星载电池充电·人造卫星所在位置的太阳能通量密度[单位面积的太阳能功率为S，卫星正
对着太阳。假设整颗卫星的发射率（又称辐射率）为e，卫星两侧的温度分别为T1和T2，o是Stefan-
Boltzmann常数。
三
Surface area A
(a)[2]What is the net heat flux [energy per second]absorbed by the bright side (the side facing towards Sun)of
the satellite
(a)[2]卫星的亮面（面向太阳的一面）吸收的净热通量[每秒能量]是多少？
(b)[1]What is the net heat flux [energy per second]released from the dark side of the satellite
(b)[1]从卫星暗面释放的净热通量[每秒能量]是多少？
(c)[1]What is value of the emissivity e to get the theoretically maximal charging power Pmax
(c)[1]可得到理论上最大充电功率Pmax的发射率∈的值是多少？
(d)[3]Find a condition for the temperature Ti in order to get the theoretically maximal charging power Pmax
provided by the satellite.Express the condition in tem of the dimensionless variableYoudon't need to
solve the equation in this part.
(d[3]求温度T的条件，使得卫星能蓬到理论上最大充电功率Pmax·用无量纲变量x=表示你的答
案。你不需要解这部分的方程·
(e)[3]What is the theoretically maximal charging power Pmax provided by the satellite Calculate the numerical
value of Your answer should be correct to at least 2 significant figures.
AS
()[3)]卫星可提供的理论上最大充电功率Pmax是多少？计算m严的数值。你的答案至少应正确到2位有
AS
效数字·
Solution:
(a)
Q1=EA(S-OT)
1
