Find the knowledge points of physical speed, velocity, average velocity, and instantaneous velocity,

Velocity in high school physics is defined as: the ratio of displacement to time, and it has a direction and is a vector. (Note the difference between speed in junior high school and math, which are not rigorous).

The ratio of displacement to time over a period of time reflects the average effect of the speed of motion during this period, so it is also called average velocity, and the average velocity is also a vector.

The velocity at a certain moment is called the instantaneous velocity, and the magnitude of the instantaneous velocity is called the velocity. The ratio of distance to time in junior high school, we can only call it the average rate now, and there is no direction.

The velocity in physics can represent the direction, first set a positive direction, then the speed of this direction is positive, its reverse direction is negative, the rate is the same as the speed in mathematics, only the size, not the direction, the average velocity is the displacement of the object compared to the time to find, according to the positive and negative displacement, the average velocity is also positive and negative, the chronological velocity is the speed at a point, often on the dot timer to make this kind of problem, this kind of problem has a specific method, the chronological velocity of 2 points is equal to the average velocity of the two points before and after.

Velocity is directional, it is a vector. The rate is only a size, and it is a scalar quantity. Average speed = distance time. When t is small enough, the velocity at a certain point is his instantaneous velocity.

The velocity is the speed of the object's motion, or the equivalent of the rate of change of the distance. It is referred to as velocity in junior high school physics, but it should be distinguished from velocity in high school physics.

It is the ratio of the distance s traveled by the moving object to the time t taken to pass this distance. i.e. (s1-s0) (t1-t0).

To make the description more precise, δt can be made smaller. If δt is very, very small, then it can be said that δs δ t represents the velocity of the object at time t, and this velocity is called the instantaneous velocity, and the magnitude of the instantaneous velocity is usually called the velocity.

1. Definition: The average rate is the distance (route traveled) per unit of time; The average velocity is the displacement per unit of time (the vector of the first and last positions of the particle over that time).

Second, the rate has only one size, which is a scalar; In addition to the magnitude, the velocity also has a direction, and the direction is the tangent direction of the trajectory curve at this time, which is the vector;

3. Formula: average rate = distance time; Average velocity = displacement time;

Maybe the above is more abstract, let me give you an example:

You go to school in the morning and take a detour to a snack bar for breakfast, which means that you go from point A to point B and then to point C, then your average rate is the route you have traveled divided by the time it takes you; But the average speed is the time it takes to get from your home to school (equivalent to a straight line), which means that the average speed has nothing to do with how we get there.

It is important to note that the velocity is the magnitude of the velocity, but the average velocity is not necessarily equal to the magnitude of the average velocity, and if it is equal except by coincidence, it means that we are strictly following the displacement vector.

Senior 1 PhysicsInstantaneous speedSeeking the Method:Take the thick position of the branch in a short period of time before and after, remove it with a linear motion if the time is uniform.

The usable intermediate velocity is equal to the average velocity.

Come and ask; If the displacement from the third second to the fifth second is known, the instantaneous velocity of the fourth second is equal to the average velocity from the third second to the fifth second, and the bits from the third second to the fifth second are removed by 2 seconds.

The velocity of a moving object at a certain moment or position is called instantaneous velocity, or velocity for short. Instantaneous velocity is a vector, and the direction of the instantaneous velocity at a certain moment (or through a certain position) is the direction of the motion of the object at that moment (or through a position). If the object moves in a straight line at a uniform speed, and its velocity remains the same during the motion, then the instantaneous velocity at any moment of its motion and the average velocity of the whole motion are also the same.

The calculation formula is different for different forms of exercise.

1. If it is a uniform motion, the instantaneous speed remains unchanged.

2. If it is a uniform and violent linear motion, the formula is: V(T)=V0+AT.

3. If it is a free fall movement.

v(t)=gt。

4. If it is an upward throwing motion: v(t)=v0-gt.

5. If it is a downward throwing motion: v(t)=v0+gt.

6. If it is a flat throwing movement.

The parallelogram rule needs to be utilized.

Decompose, and then find the velocity.

v(t) = root number [v0 square + (gt) squared].

Instantaneous velocity refers to the velocity at a certain point. Generally, the instantaneous velocity at a certain point in time can be obtained by deriving the distance from the time, and then substituting it at a certain point in time. Instantaneous velocity is a vector quantity that has both magnitude and direction. Instantaneous velocity is a quantity in an ideal state.

Linear motion with uniform velocity: The average velocity of an object in the time interval from t to t + t is s t, and if t is infinitely connected and close to 0, it can be considered that the state represented by s t is the velocity of the object at time t. In a linear motion with uniform speed, the average velocity of a certain period of time is equal to the instantaneous velocity at the intermediate moment (i.e., the instantaneous velocity at the intermediate moment).

Normal Motion: Only estimates can be found. Extend to the left and right sides for a period of time x t tending to 0.

Constant velocity: The average velocity is the instantaneous velocity. The speed of a uniform linear motion is the average velocity.

Instantaneous velocity is referred to as velocity (usually referred to as average velocity), but when the word "speed" is encountered in problem solving and academics, it refers to instantaneous velocity unless otherwise specified. Theoretically, the instantaneous velocity is only an estimate, and the exact calculated time should be infinitely close to 0, but not 0.

Direction: The direction of the instantaneous speed book vertical handicap, that is, the tangential direction of the point's motion on the trajectory.

Instantaneous velocity and average velocity: In linear motion with uniform velocity, the average velocity of the motion of the object is equal to the instantaneous velocity at intermediate moments.

Instantaneous velocity refers to determining the magnitude and direction of velocity at a moment.

Instantaneous velocity is a vector, that is, the velocity of the point between precessions at a certain time, and the average velocity refers to the value of the time when the bit is removed, reflecting the average magnitude of the velocity over a period of time.

Instantaneous acceleration refers to the sum of the external force at a certain moment divided by the mass to obtain the book Zen value, which is a vector, reflecting the situation at a certain time, and is specific to the point in time.

No matter what the speed is, there is a direction, a size; And the rate is only the size; The average speed is the total distance divided by the total time!

The average rate is the magnitude of the velocity; Instantaneous velocity is the magnitude and direction of velocity at a certain moment, while instantaneous velocity is just magnitude.

1 Velocity: A physical quantity that describes the speed of an object, with size and direction, and is a vector 2 Average velocity: A rough description of the speed of motion, which is also a vector, numerically the ratio of displacement to time.

3 instantaneous velocity: more accurate description of the speed of motion, can also be understood as the limit value of the average velocity 4 rate, the magnitude of the velocity, only the magnitude has no direction, is the scalar 5 average velocity, not the magnitude of the average velocity, the numerical value is the ratio of distance to time, is the scalar 6 instantaneous velocity, the magnitude of the instantaneous velocity, is the scalar.

The connection and difference between average velocity and average velocity is that average velocity is a vector quantity, which has both a quantity value and a direction, while average velocity has no direction, it is just a scalar quantity. Therefore, in daily calculation statistics, the written value is the velocity, and if it is given a direction, the velocity can be marked.

Instantaneous velocity and velocity are also the same connection and difference, one is a vector, there is a direction, there is a value. The other is a scalar quantity, which has no direction, only a quantity value.

As for the average velocity and the instantaneous velocity and rate, there is no direct linear relationship.

If you know a little bit more about math, you'll understand this.

The average speed is s t

When t approaches 0.

The average velocity is the instantaneous velocity. This is from a mathematical point of view. Once you've learned derivatives (it's calculus, but you need to learn a little bit in high school), you'll understand it completely.

Now you think so. For example, in a short period of time, ask you the average speed, and the displacement time is divided by the old line. When asked about your homeopathic speed, you will ask what time of the day it was.

However, due to the short period of time, it can be seen that the speed of this segment is constant (as if it passes too quickly and you don't see every moment in it), so that the instantaneous speed at any moment is the same.

It's also equal to the average speed of this segment.

Got it! ~