# Yahoo奇摩 網頁搜尋

廣告

1. ### 一秒是多少？

1960年以前，1 Second = 1/86400 Mean Solar day 。 1960~1967，一秒為平均太陽年之31556925...作為秒定義。即1 Second = 1/86400 Mean Solar day 。 1960~1967年CIPM改以更穩定的...

分類：科學及數學 > 數學 2006年11月29日

2. ### calendars

... to vary slightly during the year, or it may be averaged into a mean solar day . Other types of calendar may also use a solar day .  Calendar...

3. ### 有關Astronomy

1.Can the solid rocket boosters be switched off during the flight? 2.They can be switched off. 3.Nowadays, rocket boostes are commonly found in other rockets (eg. Ariane and Chang Zheng). 4...

5. ### 點解我們會有日夜/ why we have day and night

...934 solar hours or 24 sidereal hours) 1 solar day = a single rotation of a planet with respect to its...arc. The combination of these two factors means that light reaches the ground when the...

6. ### 地球為什麼會自轉 。why does the earth rotate?（５點）

...distance of about 150 million kilometers (93.2 million miles) every 365.2564 mean solar days (1 sidereal year). From Earth, this gives an apparent movement of...

7. ### 為什麼一小時是六十分鐘???????

...為基礎，定義以平均太陽日之86400分之一作為秒定義。即1 Second = 1/86400 Mean Solar day 。 1960~1967年CIPM改以更穩定的『地球公轉』週期為基礎，定義西元1900...

分類：科學及數學 > 數學 2006年11月23日

8. ### University Physics

... there are 10 sideral days in one year, there will then be 9 solar days . Hence, duration of one solar day = 10/9 sideral day = 1.11 sideral day 3. (a...

9. ### what's the meaning of atmosphere?

... atmosphere protects life on Earth by absorbing ultraviolet solar radiation and reducing temperature extremes between day and night.

分類：科學及數學 > 化學 2007年10月04日

10. ### Greenwich time

... scales are conventionally specified using traditional means of specifying days , carried over from non-uniform time standards based on the rotation...

分類：科學及數學 > 地理學 2006年12月12日

廣告