# 大一 物理

有些題目不是很了解

我挑了幾題

大大們替我解謎

1.For small angles θ, the numerical value of sinθis approximately the same as the the numerical value of tanθ. Find the largest angle(in radians and in degrees) for which sine and tangent agree to within two significant figures.

2. A certain audio compact disc (CD) contains 783.216megabytes of digital information. Each bytes consists of exactly 8 bits. When played, a CD player reads the CD’s digital information at a constant rate 1.4megabits per second. How many minutes does it take to read the entire CD?

3. The density of an object is defined as its mass divided by its volume. Suppose the mass and volume of a rock are measured to be 8g and . To the correct number of significant figures, determine the rock’s density.

4. Recent findings in astrophysics suggest that the observable Universe can be modeled as a sphere of radius light-years with an average mass density of about , where only about 4% of the Universe’s total mass is due to “ordinary” matter(such as protons, neutrons, and electrons). Use this information to estimate the total mass of ordinary matter in the observable Universe.(1 light-year = )

5. A stone is thrown vertically upward with a speed of 24.0m/s. (a) How fast is it moving when it reaches a height of 13.0m? (b) How much time is required to reach this height? (c) Why are there two answers to (b)?

如果有解釋那是更棒了^^

歡迎各大好手幫忙

### 1 Answer

- 1 decade agoFavorite Answer
題目很多 我先拋磚引玉來解前二題好了

也當作來複習以前的普物

因為您只要看的懂會解題就好..我就不翻的字字精準了..

1.For small angles θ, the numerical value of sinθis approximately the same as the the numerical value of tanθ. Find the largest angle(in radians and in degrees) for which sine and tangent agree to within two significant figures

中文如下

有一角度 sinθ 他的值近似於 tanθ

請看圖用radians 和 degrees 分別求出 sinθ與 tanθ最大的角度

(ps. radians 和 degrees是數學專用單字..我印象中是徑度與弧度之類的 ..這兩者間的關係有公式可以互換)

2. A certain audio compact disc (CD) contains 783.216megabytes of digital information. Each bytes consists of exactly 8 bits. When played, a CD player reads the CD’s digital information at a constant rate 1.4megabits per second. How many minutes does it take to read the entire CD?

中文如下:

byte:位元組

megabyte:百萬位元組

(因為mega的簡寫為M,M在工程是十的六次方)

bit:位元

上述名詞請參見計算機概論等相關書籍

一CD有783.216個megabyte..每1byte有8bits..每秒1.4megabits..

當要讀取此CD時..

多少時間可以讀取到此CD上的資料?

其實我猜您是大一新生..所以對原文書很恐慌

我以前也是..但家聚時學長說..原文書只要看個100頁就會習慣了 ..所以..加油囉..您會克服的..這是必經之路..

另外..理工英文書只要看的懂專業單字或是看懂電路圖就會變的很輕鬆..所以像上述的題目...只要去找關鍵字來解題就好..其他不痛不癢的不懂單字可以不用理他...反正..題目解的出來就好..

Source(s): 國立大學電機系