“2019年USAAAO决赛第2题”的版本间的差异
来自astro-init
Jingsong Guo（讨论 | 贡献） |
Jingsong Guo（讨论 | 贡献） |
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==英文题目== | ==英文题目== | ||
| − | 2. (7 points) On the night of January 21st, 2019, there was a total lunar eclipse during a supermoon. At the time, the moon was close to perigee, at a distance of 351837 km from the earth, which was $$1.4721 | + | 2. (7 points) On the night of January 21st, 2019, there was a total lunar eclipse during a supermoon. At the time, the moon was close to perigee, at a distance of $$351837 km$$ from the earth, which was $$1.4721\times 10^8$$ km from the sun. The gamma (γ) of a lunar eclipse refers to the closest distance between the center of the moon and the center of the shadow, expressed as a fraction of the earth’s radius. For this eclipse, $$γ = 0.3684$$. Given this information, find the closest estimate for the duration of totality of the eclipse. |
2020年3月7日 (六) 17:38的最新版本
英文题目
2. (7 points) On the night of January 21st, 2019, there was a total lunar eclipse during a supermoon. At the time, the moon was close to perigee, at a distance of $$351837 km$$ from the earth, which was $$1.4721\times 10^8$$ km from the sun. The gamma (γ) of a lunar eclipse refers to the closest distance between the center of the moon and the center of the shadow, expressed as a fraction of the earth’s radius. For this eclipse, $$γ = 0.3684$$. Given this information, find the closest estimate for the duration of totality of the eclipse.
