Understanding Physics ( 了解物理 )
Physics is study of the natural phenomena and the properties of matter .
=物理学是自然现象和物质的性质研究。
Understanding Base Quantities and Derived Quantities ( 理解基本的数量和派生量 )
1. A physical quantity is any quantity that can be measured by scientific instrument .
= 任何一个物理量都可以用科学仪器来测量。
2. The value of the measurement consists of a magnitude and a unit .
=它是由magnitude和unit来测量value。
3. Other examples of physical quantities are Velocity (v) , Force (F) , and Time (t) .
=物理量的另一个例子是速度(V),力(F)和时间(t)。
4. A base quantity is a physical quantity which cannot be defined in terms of other physical quantities .
=一个基本的数量是一个物理量,不能在其他物理量的界定。
5.The five base quantities are length (m) , mass (kg) , time (s) , temperature (k) , and electric current (A) .
=这五个基地数量有:长度 (m) ,质量 (kg) ,时间(s) ,温度 (s) 和电流 (k)
6. Examples of scientific instrument stopwatch , metre rule , balance thermometer , ammeter .
=科学仪器的例子:秒表,米尺,平衡温度计,电流表。
7. The International System of Units , known as SI , is based on the metric system of measurements .
=国际单位制,为 SI ,是一种基于测量的公制。
8. A derived quantity is a physical quantity which can be defined through multiplication , division or both these operations .
=派生的数量是一个物理量,可以通过乘法,除法或两者用来操作这些定义。
9. For easier recording and comparison , very large or very small measurement of physical quantities are represented by ''prefixes'' as shown in the table below.
=为了便于记录和比较,非常大或非常小的物理量测量为代表的叫做''前缀'' ,如下表所示。
Prefix | Symbol | Multiplication factor | |
---|---|---|---|
yotta | Y | ||
zetta | Z | ||
exa | E | ||
peta | P | ||
tera | T | ||
giga | G | ||
mega | M | 1 000 000 | |
kilo | k | 1000 | |
hecto | h | 100 | |
deka | da | 10 | |
deci | d | 0.1 | |
centi | c | ||
milli | m | ||
micro | µ | ||
nano | n | ||
pico | p | ||
femto | f | ||
atto | a | ||
zepto | z | ||
yocto | y | 10-24 |
10. The prefixes are usually used to simplify the expression of very large or small number .
=前缀通常用来简化非常大的或小的数目
11. The 11 derived quantities are area , volume , density , velocity , momentum , acceleration , force , pressure , weight , work and power .
=这11项派生数量有:面积,体积,密度,速度,动量,加速度,力,压力,重量,工作 和力量。
12. Scientific notation is the way that scientist easily handle very large numbers or very small numbers.
=科学记数的方式是方便科学家们处理大量或非常小的数字
13. For example, instead of writing 0.0000000056, we write 5.6 x 10-9. So, how does this work?
=例如,不要写成0.0000000056,我们写5.6 × 10-9. 那怎么做?
14. We can think of 5.6 x 10-9 as the product of two numbers: 5.6 (the digit term) and 10-9 (the exponential term).
=我们可以把5.6 × 10-9为两个数的乘积:5.6(该数字学期)及10-9(该指数项)。
15. Here are some examples of scientific notation.
=下面是科学记数法的一些例子。
10000 = 1 x 104 | 24327 = 2.4327 x 104 |
1000 = 1 x 103 | 7354 = 7.354 x 103 |
100 = 1 x 102 | 482 = 4.82 x 102 |
10 = 1 x 101 | 89 = 8.9 x 101 (not usually done) |
1 = 100 | |
1/10 = 0.1 = 1 x 10-1 | 0.32 = 3.2 x 10-1 (not usually done) |
1/100 = 0.01 = 1 x 10-2 | 0.053 = 5.3 x 10-2 |
1/1000 = 0.001 = 1 x 10-3 | 0.0078 = 7.8 x 10-3 |
1/10000 = 0.0001 = 1 x 10-4 | 0.00044 = 4.4 x 10-4 |
16. In scientific notation, the digit term indicates the number of significant figures in the number.
=在科学记数法,长期的数字显示在有效数字位数的号码。
Understanding Scalar Quantities and Vector Quantities .( 了解标量和矢量量。)
1. Scalar quantity is a physical quantity which has magnitude or size only .
=标量是一个物理量的数量或大小而已。
2. The examples or scalar quantities include distance , speed , volume , temperature , and time .
=这些例子或标量,包括距离,速度,体积,温度和时间。
3. Vector quantity is a physical quantity which has direction as well as magnitude .
=矢量是一个物理量,有方向和大小。
Understanding Measurements (了解测量)
1 -Consistency- (一致性)
The consistency of a measuring instrument is the ability of the instrument to produce readings that are consistent with little or no variations in the different readings of the same physical quantity.
=一个测量仪器的一致性是仪器读数的能力的产生与在同一物理量的不同读数很少或根本没有变化相一致。
2. - Accuracy (准确性)
The accuracy of a measurement is the proximity of the measurement to actual value of the quantity measured .
=一个测量精度是测量距离量测到的实际价值
3. - Sensitivity - (灵敏度)
The sensitivity of an instrument is the ability of that instrument to detect small changes in the quantity being measured .
=对仪器的灵敏度是该仪器能够检测的数量被测量的微小变化。
4. - Systematic Errors - ( 系统误差 )
Systematic errors are errors caused by the condition of the measuring instrument or the state of the environment in which the measurement in which the measurement are taken .
=系统误差是由测量仪器的条件或在其中的测量中,测量采取的环境状况引起的错误。
5. - Zero Error - (零误差)
Zero error refers to error in instrument that do not show zero reading when its reading should be zero .
=零误差是指在仪器误差不显示零读数时,其读数应为零。
6. - Random Error - (随机误差)
Random error are error due to the experimenter's inability to take the same measurement in exactly the same way to get the exact same number .
=随机误差的错误是由于实验者的无力采取完全相同的方式来获得同样数量的相同精确测量。
7. - Parallax Error - (视差)
Parallax error is the error due to the incorrect positioning of the eye .
=视差是错误是由于眼睛不正确的定位。
8. - Experimental error - (实验误差)
Experimental error or uncertainly refers to the difference between measured value of a quantity and its actual value .
=实验误差或不确定性是指测量值之间的数量和其实际价值的差额。
Understanding Measuring Instrument (了解测量仪)
1. - Measuring Cylinder - (量筒)
The measuring cylinder is used to determine volume of liquid
=量筒用于确定液体的体积。
2. - Ammeter - (电表)
The ammeter is used to measure electric current .
=电流表是用来测量电流。
3. - Meter rule - (米尺)
The meter rule is used to determine the length accurately up to 0.1cm only .
=米尺是用来确定准确的长度可达0.1公分而已
4. - Micrometer screw gauge - (螺纹千分尺规)
The micrometer screw gauge can be used to measure very small lengths such as the diameter of a wire or the thickness of a piece of paper as it can measure length accurately up to 0.01mm .
=螺纹千分尺测量,可用于测量非常小的长度,如金属线的直径或一张纸,因为它可以精确地测量长度可达0.01mm的厚度。
5. - Vernier Calipers - (游标卡尺)
Vernier Calipers can measure length with an accuracy of up to 0.01cm .
=游标卡尺可以测量的准确度到0.01厘米
6. - Stopwatch - ( 秒表 )
The analogue stopwatch measures time in intervals of 0.1s .
=秒表测量时间的模拟在0.1秒的间隔
7. - Digital Stopwatch - (电子秒表)
The digital stopwatch measures time in intervals of 0.001s .
=秒表测量时间的模拟在0.01秒的间隔
8. - Triple beam balance - ( 三重平衡梁 )
A triple beam balance can measure the mass of an object with an accuracy of 0.1g .
=一个三重平衡可以测量0.1克的物体的质量的精度。
* Ammeter and milliammeters must be connected in series in an electrical circuit because these meters have very low resistance .
=电流表和milliammeters必须连接在一个电路,因为这些meters,具有非常低的电阻串联。
- END FROM CHAPTER 1 -
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