In senior high school physics compulsory one, there is an experiment of uniform linear motion, which requires the instantaneous velocity of a point on the paper tape. I know it needs to be estimated when measuring the displacement. But what about the velocity obtained by dividing the displacement by time? What about the acceleration? If the difference between the two displacements is just an integer? Do you want to add. 000 after the velocity

In senior high school physics compulsory one, there is an experiment of uniform linear motion, which requires the instantaneous velocity of a point on the paper tape. I know it needs to be estimated when measuring the displacement. But what about the velocity obtained by dividing the displacement by time? What about the acceleration? If the difference between the two displacements is just an integer? Do you want to add. 000 after the velocity

High school physics experiment questions retain two decimal places, the answer questions retain one place
You can also look at the question to retain a few significant figures
In addition, the college entrance examination questions are clearly defined

The difference and relation between velocity and instantaneous velocity
For example, these physical quantities are always confused. Can we make them easier to understand,

Let me add a little
Speed is the speed of an object's movement, or the rate of change equivalent to the distance. It is called speed in junior high school physics, but it should be distinguished from the speed in senior high school physics
It is the ratio of the distance △ s passed by a moving object and the time △ t taken to pass the distance, i.e. (S1-S0) / (t1-t0)
In order to make the description more accurate, we can make Δ t smaller. If Δ t is very small, we can think that Δ s / Δ T represents the velocity of the object at time t, which is called instantaneous velocity, and the magnitude of instantaneous velocity is usually called velocity
1、 Definition: the average speed is the distance in unit time (the route passed); the average speed is the displacement in unit time (the vector of the first and last positions of the particle in this period)
2、 Velocity has only one size, which is scalar; besides size, velocity has direction, which is the tangent direction of the trajectory curve, which is vector;
3、 Formula: average speed = distance / time; average speed = displacement / time;
Maybe the above is more abstract. Let me give you an example
When you go to school in the morning, you make a detour to a snack bar for breakfast. That is to say, you first go from a to B and then to C. then your average speed is the total route you have traveled divided by the time you spent. But the average speed is the vector (equivalent to a straight line) / the time you spent from your home to school. That is to say, the average speed has nothing to do with the way we arrived
It should be noted that the velocity is the magnitude of the velocity, but the average velocity is not necessarily equal to the magnitude of the average velocity

The average speed and the average speed may be different, but the instantaneous rate and the instantaneous speed must be the same?
Give me the answer by two o'clock-
I think that the speed of one car is 2m / s, and that of the other car is 3m / s. their average speed is not equal to the average speed. Will the instantaneous speed be equal to the instantaneous speed?

The average velocity is equal to the ratio of the distance to the time used, which is a scalar. The average velocity is equal to the ratio of the displacement to the time used, which is a vector

Velocity is the ratio of displacement to time, and velocity is the ratio of distance to time
Then why is the instantaneous velocity always equal to the instantaneous velocity?

First of all, we need to understand the concept of velocity, which refers to the displacement corresponding to a period of time when an object is moving. Usually, this period of time is called unit time, but unit time can be changed. When the unit time is infinitesimal, the obtained velocity is instantaneous velocity, because in most cases, the displacement corresponding to infinitesimal time is also very small. At this time, the distance

(high school physics) the magnitude of instantaneous velocity = instantaneous velocity. Is this sentence only applicable to linear motion?

No, this applies in any case

The velocity of the particle passing through point a is 3m / s, which means ()
A. The displacement of the particle in the first second after passing through point a is 3MB. The displacement of the particle in the first second after passing through point a is 3mc. If the particle moves in a uniform speed changing straight line, the displacement of the particle in the second with the time of point a as the middle time is 3MD. If the particle moves in a uniform speed changing straight line from point a, the displacement in every second after passing through point a is 3M

Ab. because the particle moves in a variable speed straight line, the velocity before and after point a is not equal to 3m / s, then the displacement of the particle before or after point a is not necessarily equal to 3m, so a and B are wrong. C. if the particle moves in a constant speed straight line, the instantaneous velocity in the middle is equal to the average velocity, so the displacement in the middle is equal to 3m, so C is correct Linear motion, the displacement per second is not equal to 3m

An object moves along a straight line: (1) if the average velocity in the first half of the time is V1, and the average velocity in the second half of the time is V2, find the average velocity in the whole process. (2) if the average velocity in the first half of the displacement is V1, and the average velocity in the second half of the displacement is V2, what is the average velocity in the whole process?

(1) Suppose the displacement of the first half of the time is S1, the displacement of the second half of the time is S2, and the time of the whole process is t, then S1 = v1t2s2 = v2t2, then the average velocity of the whole process is. V = S1 + s2t. The simultaneous solution is. V = V1 + V22 (2) suppose the time of the first half of the time is T1 ', the time of the second half is T2', and the whole process displacement is s. according to the kinematic formula, there are: T1 '= s2v1 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; T 2 ′ = s 2V 2, then the average velocity of the whole course is v 1 + V 22. (2) if the average velocity of the first half is v 1, the average velocity of the second half is v 2, and the average velocity of the whole course is v 1 + V 22. (2) if the average velocity of the first half is v 1, the average velocity of the second half is v 2, and the average velocity of the whole course is v 1 + V 2

High school physics. What is speed? What is average speed? Speed, average speed?

There is a winding mountain road between two cities a and B. a truck is driving from a to B
Speed: the speed of a car at a certain time
Average speed: total length of mountain road divided by travel time t
Velocity: the ratio of displacement to time taken
Average speed: the linear length between a and B divided by time t

The ratio of displacement to the time taken for the displacement to occur
In variable speed linear motion, the ratio of the displacement of a moving particle to the time taken
1. Does the average velocity have to be linear
2. What's the difference between the time used for this displacement and the time used?
It's best to give an example

1. If the average velocity is not calculated in a straight line motion, but in a curve motion, the direction of velocity will change at any time, and the calculated V is meaningless. Even if v = s / T is used, because in a curve motion, the displacement, that is, the line between the starting point and the end point, is generally at a certain angle with the horizontal direction, so the direction should be represented by cos

A lot of people don't understand
1. For a certain section of road, the average displacement speed of the front section is 3m / s, and the average displacement speed of the back section is 2m / s. how to get the average speed of the whole course, 4m / S?
2. The average speed is 27km / h. how to find V1

Your first question should be the first half and the second half? Set the whole process as 2S, the first half and the second half as s, the first half is s / 3, the second half is s / 2, then the total time is 5S / 6, and then divide the total time by 2S
Second: if the total distance is 3S, the first third of the time is s / V1, and the last two thirds of the time is 2S / 20, then the total time is (20s + 2sv1) / 20v1. Then divide the total distance by 3S, and the total time is equal to the average speed of 27. Form a one variable linear equation, and the solution is equal to 90