It s about to take the exam.,Find which student is proficient in high school mathematics and physics

- Wow wow, what a lot.

You give me q.,I know it's as good as I can say.,But it seems like I've basically forgotten about the first year of high school.,I forgot what the log was.。。

Kids who know how to use online features to learn, thumbs up!!

When you say log, you think of it as a root number, square, addition, subtraction, multiplication, division and the like, which means to find the power of a number is equal to this number, such as loga1, the meaning expressed is to find the power of a is equal to 1, and the power of 0 of a is equal to 1, so there is loga1=0. Here a can not be 0, negative, 1, because any power of 0 must be 0, any power of 1 must be 1, the even power of negative numbers is positive, the power of cardinality is positive, when a is and negative, it is not conducive to using the formula log to summarize and deduce mathematical formulas, here rote memory a can not be negative, that is, there are negative numbers and zeros you said there is no logarithm. As for the rest, I really forgot what the formula means to pull, you can list the formula and take a look.

To learn mathematics, you need to look at the definition of the formula, understand the definition, it is very simple, understand the most basic formula definition, and other formulas can be calculated by yourself. Here's a bottom change formula for you to see, very detailed.

Uniform acceleration of linear motion.

Speed formula: vt=v0+at, the time required to brake is equivalent to vt is 0, giving you an initial velocity vt and deceleration a to find time t. It should be a deceleration so this a is a negative number, and a formula has only one unknown time t pull, which is very easy to find.

No matter how he changes the braking problem, you just need to find a way to find the initial velocity and deceleration, because the final velocity vt is 0, you must be able to find the braking time t.

This knowledge is too long, I don't remember it very well, I say it more colloquially, forgive me, it is recommended to read more formulas in the encyclopedia, and your textbook. The best is the textbook, just look at those definitions and example questions, as long as you understand the pull, find more questions to pull and adapt. Sometimes the questions can be practiced less, the key is to look at the formula definition and example questions, the most important thing in the mathematics test is the formula definition and example questions, only when you understand the formula definition and example problem pulling, can you have the ability to draw inferences from one another to do other questions.

Hello! Suppose the equation log a b=c is equivalent to the c power of a = b then you should understand the first problem of math Second, why are negative numbers and zeros not logarithmic? Because it doesn't make sense, we only study positive numbers in high school, and if you go to math in college, you get to the logarithms of negative numbers.

Thirdly, there is a formula that you should know, which is log a c d = loga c + loga d, so by the formula just now, the nth power of m in your third question is equivalent to the multiplication of n m, and by the formula it becomes the addition of n loga m. The fourth formula for changing the bottom is detailed in . If you don't know yet, leave a QQ for me to score with pure hands.

1. Log and lg are logarithmic functions, the difference is that lg is based on 10; e is a constant, similar to .

2. Let the braking distance = s, the initial velocity is v, the acceleration is a, and the braking time is t; Then s=1 2at 2, v-at=0, s and v are known data, and a and t can be found by the above two equations

1. Mathematics. There are formulas for that log, lg, e, or something, and I can't understand them in class, and I can't remember them all, so please tell me what's going on, and you want to list all the formulas to me.

2. Physics. Constant acceleration speed will not be the content, for example, the brake does not know how to find the time required for braking, etc., but also to list the formula for me, to explain what those letters represent, I want to understand.

Completely understand the talent.

Question added: Well, memorize on the basis of understanding, well said, please forgive me for not being able to express it, I mean this, as for the zero power of 5, I know that it is 1, but what I am struggling with is, is the zero power of 0 1? According to the teacher, the power of zero is the product of another number, which is 1, so shouldn't zero be 0?

As for other examples, multiplication is the addition of numbers under log, I really can't understand it, I really can't remember it.

Mathematical: first, log a 1=0, log a a=1

Why. Clause.

2. There is no logarithm between negative and zero.

Why. Third, log a m to the nth power nlog aa m (n belongs to r).

What does it mean and why?

Clause. Fourth, how to get the formula for changing the bottom, and what are a, b and c.

The above is still the main explanation, after understanding, I have to do the question I typed, and then explain it to me.

Physical: Straight lines with uniform velocity.

To request or insert **, click the title to go to the issue details page.

In fact, it's better for you to calm down and read the textbook than to find someone to talk to.

Math: First, loga 1=0 because a to the power of 0 is equal to 1log a a=1 because the 1 primary square of a is equal to a

If a is to the power of n is equal to x (a is greater than 0 and a is not equal to 1), then n is called the logarithm of base x with a and denoted as n=logax where a is called the base of the logarithm, x is called the true number, and n is called the "logarithm of a base x". More directly, in log a x, a is the base in the original exponential function, and x is the number obtained in the original exponential function, which is the result. Log a x is the exponential part of the original exponential function.

Second, in an exponential function, a to the power of any power (i.e., x) is greater than 0. So in a logarithmic function, x cannot be negative and 0

Third, log a m to the nth power can be written as log a(m*m....m)=(loga m)+(loga m)+.loga m=nloga m because, if you think about it, in an exponential function, a to the power of 2 (logax=2) multiplied by a to the power of a (logay=3) is equal to a to the 5th power of a (logaz=5).

From this, it can be seen that x*y=z, and logax+logay=logaz.

Fourth, the formula for dipping is logab=logcb logca (abc is any number greater than 0. Of course, when doing the problem, you should choose the simplest number as possible to calculate. ）

Physics: Linear motion with uniform variable speed is much easier to understand the formula first and then memorize it.

The braking problem you are talking about is that it has an initial velocity v0, a constant acceleration a when braking, and a final velocity of 0, so the time can be calculated according to the formula v=v0-at. At this point, v=0

I will first list the commonly used formulas for linear motion with uniform variable speed: the square of v0.

There are still questions you can ask again, I can try my best. The important condition for learning physics well is understanding, not rote memorization, and it is a common problem to memorize formulas but not use them. For a motion process, we first analyze what happens in this process, and then select the required formula according to the process.

I can give you an example, for example, if you have a brake problem, if the distance is required instead of time, then you have to choose the second formula.

And our explanation is just to help you understand, but whether you can really understand it depends on yourself, physics and mathematics need to use more brains. Only by constantly thinking and constantly thinking can we make progress. I think so I am, I hope you can think more and experience the charm of mathematics and physics.

After all, math is the gymnastics of the mind!

log is the base of the ordinary number,,, lg is the base of 10 You can find it if you know the speed when braking, because when braking, the speed is zero, you know what his uniform acceleration speed is, and the time will come out.

Some knowledge can be solved, limited to high school, and the textbooks are conditional. As long as you study thoroughly, the exam will not exceed the syllabus. Do you want to know, college entrance examination mathematics major, graduate study Ph.D.

You can ask me, I'm a top student in the first year of high school.

log denotes logarithm Commonly used logarithms are lg, ln, lgn denotes logarithm (n>0) with ten as the base n. LNN denotes the logarithm (n>0) with e as the base n. The formula for changing the bottom is an logbn logba lg10=1 lne=1 math and that's it, the exam should be easy.

The title speaks of a uniform upward movement. So the object is balanced by the resultant force of the four forces. (gravity, the supporting force n of the inclined plane, f upward in the direction of the inclined plane, and the kinetic friction f down in the direction of the inclined plane).

f=f+mgsin37°

f=umgcos37°

Support force n = mgcos37°

Orthogonal decomposition of attention.

The components of the vertical bevel are the same.

The resultant force of each component along the inclined plane direction looks at the direction of acceleration.

It is to decompose MG into two directions: vertical and horizontal.

If you don't understand, ask again. Wish. Thank you.

1. Here you can decompose gravity g into the downward gliding force f1 along the inclined plane and the component force f2 perpendicular to the downward inclined plane

Then it follows that f=f1+f. f= mgcos37°, f1=mgsin37°

i.e., f=mgsin37°+ mgcos37° can be found m=f g(sin37°+cos37).

Based on the data here, it can be concluded that m is finally 6kg

The second and third questions are too tiring to type, so let's give you the answer to the equation directly.

The support force is f=mgcos37°=48n, and the friction force f= mgcos37°=24n

Solution: (1) mgsin + mgcos = f solution, m = 6kg

2) The bevel on the object support force fn = mgcos = 48 n3) friction force f = mgcos = 24 n

15, sliding; 2n；；

16, (1) scale ruler.

2) Uniform acceleration.

3）220v；；；

4）vb=(x1+x2)/

vc=（5）a=(x2-x1)/t^2=

Force analysis, the state of the support force of the ball: n=mgcos30° decomposition support force: f1=ncos30°

The vertical upward tension of the spring: f2=mg-f1

The spring is subjected to the cavernous force of the slag: f=f2 cos30° elongation: x=f k=mg root number 3 6