Curvilinear motion under what conditions can be uniform rate motion

Let's say circular motion, but I think it's the same velocity but different direction.

Uniform speed curve motion refers to the acceleration during the motion.

Motion in which the direction is different from the velocity and the acceleration is constant (i.e., the magnitude of the acceleration is constant, and the direction is also constant).

Definition. In the process of motion, the direction of acceleration is different from the direction of velocity and the acceleration is constant (i.e., the magnitude of acceleration does not change, and the direction does not change), such as flat throwing motion.

Displacement in the direction of muzzle velocity s=vot [no acceleration in the horizontal direction] displacement in the direction of acceleration h=1 2at 2 [no initial velocity in the vertical direction, i.e. vo=0] final velocity vt = gt on the vertical displacement

Note: Uniform variable speed circular motion.

The direction of acceleration changes, and the non-uniform speed curve moves. ）

, uniform acceleration movement, and uniform deceleration movement, there is no rigid, layer of unchanged difference;

The uniform acceleration curve movement in the east direction is the uniform deceleration curve movement in the direction;

Generally speaking, a, the oblique upward throwing motion, before reaching the highest point, is a uniform deceleration curve movement.

The premise of this statement is that the upward velocity is in the positive direction.

b. The oblique upward throwing motion, after reaching the highest point, is a uniform acceleration curve motion.

The premise of this statement is that the downward velocity is in the positive direction.

Through the above examples, it shows that when we make judgments, we actually have them in mind.

Reference direction. A is the reference direction in the upward direction, and in the downward in the B is the reference direction.

No. , curvilinear motion.

It means that the trajectory of the blind movement is not a straight line;

Velocity is a vector quantity, there is a magnitude and a direction, and as long as the magnitude and direction change, the velocity changes. Since it is a curvilinear motion, then at least in the direction of velocity.

It changes from moment to moment, that is, the speed changes from moment to moment.

Therefore, the curvilinear motion cannot be a uniform motion of the brother space.

Curved motion must be variable speed motion.

A false. b Yes Uniform velocity only refers to the velocity and does not refer to the direction, and the uniform circular motion can be satisfied (if the title says that the curvilinear motion can be a uniform motion, then it is wrong, because the direction of the velocity changes all the time, and the magnitude of the velocity does not change).

C false. D false. Therefore, choose B

Pick B. The speed of the curve movement can be constant, but the direction must change, a is wrong and B is right, as long as the speed change (direction or magnitude) must have acceleration, the acceleration can be constant (flat throwing motion), or it can be variable (circular motion) cd is wrong.

The answer is far bCurvilinear motion must be variable speed motion, its direction changes all the time, and its acceleration can be variable or unchanged, such as uniform circular motion and flat throwing motion.

a. Curve motion is not necessarily variable speed motion.

Say the common solution to you. Application: The instantaneous velocity in the middle is equal to the average velocity over this period of time.

Therefore, you only need to take the point where the speed is required, and find another point before and after it, and you can use that point as the intermediate point between these three points.

Then use the average velocity of the total displacement of the total time, add up the displacement of the two periods before and after this point and divide it by the corresponding two periods of time, and you can do it.

For example, if there are five consecutive points of ABCDE and the instantaneous velocity of point B is required, then VB (ab+bc) 2t, where t is the continuous time interval.

Uniform motion generally refers to uniform linear motion.

That is, the magnitude of the velocity does not change the direction.

Therefore, curvilinear motion cannot be uniform motion.

Uniform circular motion is a special name. Strictly speaking, it is not a uniform motion.

It's just the same size, but the direction is changing all the time.

So it's not.

Velocity seems to be a vector quantity, there is a magnitude and direction, and curvilinear motion is a force on an object that changes the direction and magnitude of velocity. If we only talk about velocity, a uniform circular motion is a uniform motion, and if we consider the directionality of velocity, there is no uniform motion in curvilinear motion.

Because velocity is a vector, uniform motion requires that the magnitude and direction of velocity do not change, while curvilinear motion obviously changes the direction of velocity, so curvilinear motion cannot be uniform motion. Uniform circular motion can only be said to be a uniform motion and cannot be said to be a uniform motion.

is a uniform motion, where velocity refers to the velocity;

It is not a uniform linear motion, the velocity is a vector, there is both a magnitude and a direction, and only the one that remains the same in magnitude and direction is a uniform linear motion.

As a question of judging right or wrong, this statement is not true!

Strictly speaking, a curvilinear motion with constant velocity is not a uniform motion!

Speed is a vector, both in size and direction! Constant velocity generally means that the size and direction are unchanged.

But there are exceptions: such as 'uniform circular motion'. Uniform velocity here refers to uniform velocity!

Therefore, in non-judgmental questions, it is necessary to understand whether "uniform velocity" refers to speed or velocity depending on the overall meaning of the topic!

a. Since it is a curvilinear motion, the direction of its velocity must change, so the curvilinear motion must be a variable speed motion, so A is wrong and C is correct; b. Uniform speed linear motion is not a curved motion, so B is wrong; d. Under the action of constant force, the object can do curvilinear motion, such as flat throwing motion, so the curvilinear motion can be a uniform variable speed motion, so d is wrong; Therefore, c

a. The leather movement of the curve gear may be a uniform speed movement, such as: flat throwing movement, so A is wrong;

B. Since it is a curvilinear motion, the direction of its velocity must change, so the curvilinear motion must be a stupid slag velocity motion, the condition of the curvilinear motion is that the resultant force of the difference is not collinear with the velocity, there must be acceleration, and the resultant external force of the object in the curvilinear motion must not be zero, so B is correct and C is wrong;

d. The speed of the curve motion does not necessarily change, such as uniform circular motion, so d is wrong;

Therefore, choose B