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Is the speed of sound in the air average or instantaneous? Is the speed from Shanghai to Suzhou average or instantaneous?
The average speed is the speed of the process of an object from a to B, which corresponds to the time period, while the instantaneous speed is the speed at a certain time, which corresponds to the time point. The average speed of a car from Suzhou to Shanghai is the average speed. As for the speed of sound in the air, it's not easy to answer. I think it should be the average speed
I'll preview it myself. I understand the average speed and instantaneous speed in theory, but I don't understand the sentence after reading this question in the book
Question:
A particle starts from O and moves in a straight line along the x-axis. The functional relationship between its displacement and practice is x = 4T & sup2; (m)
(1) The average velocity from T1 = 3S to T2 = 5S;
(2) The average velocity from T1 = 3S to T2 = 3.1s;
(3) The average velocity from T1 = 3S to T2 = 3.01s;
(4) The average velocity from T1 = 3S to T2 = 3.001s;
It is easy to do, but there is a sentence in the book after getting the answer: the smaller the displacement is, the shorter the corresponding time is, the closer the average velocity is to the instantaneous velocity at that time
The main reason is that this sentence is not easy to understand. It's easy to explain. It's better to have specific and detailed examples to help me understand,
If you know more about mathematics, you will understand it. The average speed is △ s / △ T. when △ t approaches 0, the average speed is the instantaneous speed. This is a mathematical point of view. After learning the derivative, you will fully understand it
How to compare the motion of objects in physics
Speed is a physical quantity that indicates the speed of an object
Generally speaking, we can compare the speed of an object by measuring the distance it passes through in a certain time or the time it takes for it to pass through a certain distance
In physics, what is the speed of a moving object with variable speed
Speed is relative. Speed is a physical quantity that describes the speed and direction of an object's motion. Speed is a vector, which has size and direction. The size of speed is also called "speed". The speed mentioned in physics generally refers to the instantaneous speed, while the speed of trains and airplanes usually refers to the average speed
What is the speed of motion in physics?
Speed
What is the way to express the speed of an object in physics?
The original sentence in the second grade textbook
In physics, the speed of an object is expressed by the physical quantity of speed. See the definition and physical meaning of speed for details
Velocity is a physical quantity to describe the speed of an object, defined as the change rate of displacement with time
Speed is a vector. Junior high school definition: how much distance an object passes in unit time is called speed. Senior high school definition: speed is equal to the ratio of displacement and the time it takes to move. Symbol: v [Note: the Greek letter V stands for another physical quantity "displacement"] definition: v = s / T in the international system of units, Basic unit: meter / second (M / s) physical meaning: speed is a physical quantity describing the speed of an object. Property: vector. In the international system of units, the dimension of speed is L * T ^ (- 1), the basic unit is meter per second, and the symbol is m / s. maximum: vacuum light speed c = 299792458m / s, It is often called speed. Instantaneous speed: the speed of a moving object at a certain moment (or a certain position), which is called instantaneous speed. Average speed: the ratio of the displacement of an object passing through and the time it takes, which is called average speed (no matter what kind of motion it takes)
In the uniform linear motion, the instantaneous velocity can be understood as,
14. The instantaneous velocity can be understood as ()
A. Its size represents the speed of an object moving at a certain time. B. its size represents the speed of an object moving through a certain position
C. In the velocity time image, the larger the angle (acute angle) between the line and the time axis, the greater the change of instantaneous velocity
ABCD talked about the past one by one,
Instantaneous speed is the speed at a certain time or a certain position, that is, the speed of movement, so AB is correct
Instantaneous velocity has both magnitude and direction, so it is a vector, so C is wrong
In the velocity time image, the slope represents the acceleration, that is, the speed of speed change, so it should be said that in the velocity time image, the greater the angle (acute angle) between the straight line and the time axis, the faster the instantaneous speed change, D error
The instantaneous velocity is the velocity at a certain moment, so only the instantaneous velocity can accurately describe the variable speed motion
Correct, variable speed motion is not necessarily uniform acceleration motion, but also variable acceleration motion, and acceleration may not be clearly described
If the instantaneous velocity at each moment is known, the variable speed motion can be described accurately
Instantaneous velocity can describe the speed and direction of a moving object in or
Instantaneous velocity can describe the speed and direction of a moving object at a certain time or position
Can instantaneous velocity or average velocity accurately describe variable speed motion?
The average speed is the ratio of a period of displacement and time, it can not exactly express the speed at a certain time, only the instantaneous speed can
RELATED INFORMATIONS
- 1. 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
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