Why is the power of the centripetal force moving in a uniform circular motion zero

Why is the power of the centripetal force moving in a uniform circular motion zeroIt's not zero, but it's zero, because some scientists don't understand the relationship between mathematics and physics. The power of the centripetal force of the object moving in a uniform circular motion is a constant value, because it is constant, mathematically it is considered that this constant value can be regarded as zero, and the calculated value is unchanged, which is the root of the saying why the power of the centripetal force of the uniform circular motion is zero.

Take the pendulum as an example: the greater the length from the hanging point to the center of the pendulum, the longer the period of the pendulum. When the length of the pendulum is determined, the change in the mass of the pendulum has no effect on the period, but the position on the earth does.

When the length of the pendulum is determined, the change in the mass of the pendulum has no effect on the period, but the position on the earth does. Because the position on the earth has an effect on the period of the pendulum, which has an effect on the speed of the pendulum. It is the gravitational acceleration that varies from one location on the earth to the other, and the velocity of the pendulum changes.

The velocity of the pendulum changes, indicating that the centripetal force also changes. The gravitational force produced by the acceleration of gravity on the pendulum here is equal to the centripetal force of the pendulum, and the gravitational force and the centripetal force, which are equal in magnitude and opposite in opposite directions, act on the same straight line and react. The centripetal force can change the velocity of an object, as evidenced by this.

1.It is obtained directly from the defined force point multiplied by displacement of the work. In uniform circular motion, the direction of force and velocity is perpendicular, i.e., the object has no displacement in the direction of force, so the centripetal force does not do work, and the work and power are naturally zero.

2.It can also be seen from the kinetic energy theorem that the rate of uniform circular motion does not change, and the kinetic energy does not change, reflecting that the work done by the external force on it is 0, and thus the power is also 0.

Because the centripetal force of uniform circular motion is always perpendicular to the direction of velocity, therefore, the centripetal force does not attack, and the power is zero if it does not do work.

The centripetal force is always perpendicular to the direction of motion and does no work at all, so the power is always zero.

The centripetal force is perpendicular to the direction of motion.

Momentum is not conserved, angular momentum is conserved.

Explanation: In a uniform circular motion, the magnitude of the velocity does not change, while the direction always changes. Therefore, the magnitude of the momentum does not change, and the direction is always changing, so it is not conserved.

The magnitude of angular velocity is equal to the linear velocity state volt multiplied by the radius, so it is always unchanged, and the direction of angular velocity can be known as a vertical plane of motion by applying the right-hand spiral rule, and remains unchanged, so the magnitude and direction of angular velocity are unchanged, and the angular momentum is also unchanged. From the perspective of Libi closed science, an object moving in a uniform circular motion always receives a centripetal force with the same magnitude and direction, so this force accumulates in time to form an impulse and changes the momentum. But this regrets that there is no moment, so there is no angular impulse, so the angular momentum does not change.

Uniform circular motion 1Linear velocity v=s t=2 r t 2Angular velocity = t=2 t=2 f 3

Centripetal acceleration a=v2 r= 2r=(2 t)2r 4Centripetal force f centr=mv2 r=m 2r=m(2 t)2r 5Cycle vs. frequency t=1 f 6

Angular velocity vs. linear velocity v= r 7Angular velocity vs. rotational speed =2 n (here frequency is the same as rotational speed in the same sense) 8Main physical quantities and units:

Arc length (s): m (m) angle ( ) radian (rad) frequency (f): hertz (hz) period (t):

Second(s) Rotational speed (n): r s radius (r): meters (m) linear velocity (v):

m s angular velocity ( ) rad s centripetal acceleration: m s2 Note: (1) The centripetal force can be provided by a specific force, or by the resultant force, or by the component force, and the direction is always perpendicular to the direction of velocity.

2) The centripetal force of an object moving in a circular motion with uniform velocity is equal to the resultant force, and the centripetal force only changes the direction of the velocity, not the magnitude of the velocity, so the kinetic energy of the object remains the same, but the momentum keeps changing.

In a uniform circular motion, momentum is not conserved, and angular momentum is conserved. Uniform circular motion is the simplest form of circular motion and one of the most basic curvilinear motions. Uniform circular motion is an idealized form of motion.

If the length of the arc passing through the mass is equal in a circle, this motion is called "uniform circular motion", also known as "uniform circular motion". Because the velocity of the object does not change when it moves in a circle, but the direction of velocity changes at any time. Therefore, the linear velocity of uniform circular motion changes all the time.

1. It has initial velocity;

2. A force (centripetal force) that is subjected to a force of constant magnitude and perpendicular direction and velocity to the center of the circle.

When an object moves in a uniform circular motion, although the magnitude of the velocity does not change, the direction of the velocity changes all the time, so the uniform circular motion is a variable speed motion. And because when it moves in a uniform circular motion, the magnitude of its centripetal acceleration remains unchanged, but the direction changes at all times, so the uniform circular motion is a variable acceleration motion. The "constant velocity" in the term "uniform circular motion" simply means that the velocity is invariant.

According to the formula of centripetal acceleration in a uniform circular motion a=v 2 r= 2r, the magnitude of the centripetal acceleration of a uniform circular motion does not change, and the direction (pointing to the center of the circle) changes at all times, so the centripetal acceleration in a uniform circular motion is not a constant quantity.

The centripetal acceleration a=v2 r is applicable to both uniform and variable circular motion.

Centripetal acceleration reflects the direction of velocity in the radius direction of the circular motion (i.e., the radial immediate velocity direction·) The speed of change. In a uniform circular motion, the magnitude of the centripetal acceleration remains unchanged, and the direction points to the center of the circle; In a variable speed circular motion, a=v 2 r denotes instantaneous acceleration, and the magnitude of the centripetal acceleration changes, and the direction points to the center of the circle.

The centripetal acceleration in a uniform circular motion is not constant and changes direction.

From the known conditions given in the question, it can be determined that the trajectory of the particle is circular, and it is a uniform circular motion. Since the magnitude of the resultant external force on the particle moving in a uniform circular motion is unchanged and the direction is directed towards the center of the circle, the position of the center of the circle can be known from the equation of motion given by the problem at the origin of the coordinate system, so the moment obtained is equal to zero.

Displacement vector:r=costi+sintj

Velocity vectorsvr'=-sinti+costj

Angular momentum vectorlrxmv=m(costi+sintj)x(-sinti+costj)=m(cos²tk+sin²tk)=mk

Because the object moves in a uniform circular motion with respect to the origin, the angular momentum is conserved, so the external moment is zero.

Tangential acceleration.

In the process of uniform circular motion of the particle, the "tangential acceleration" is always zero;

During the acceleration of the mass in a circular motion, the direction of the "tangential acceleration" is always the same as the direction of the velocity.

The content of the rotation depends on the relative reel, and there is no conclusion.

There are two ways to understand it:

The first way to understand it:

According to the kinetic energy theorem, the work done by the combined external force is equal to the increase in kinetic energy.

The combined external force provides the centripetal force required for circular motion.

For uniform circular motion, the centripetal force is always perpendicular to the direction of the velocity of the motion, and this is true at any moment, the centripetal force never does work, so without work, there is no possibility of increasing the velocity.

The second way to understand:

According to Newton's second law, in a uniform circular motion, the only resultant external force is the centripetal force;

The displacement direction is in the tangential direction, and the force point is multiplied by the displacement, which is 0 at all times, so no work is done.

Because the centripetal force is always perpendicular to the velocity.