What are Newton's three laws?

What are Newton's three laws?

Newton's three laws
Newton's three laws are important laws in mechanics, which are the basis of studying classical mechanics
1. Newton's first law
Content: any object remains stationary or moving in a straight line at a constant speed until it is forced to change this state by the force of other objects
Explanation: all objects have the tendency of keeping still and moving in a straight line at a constant speed. Therefore, the motion state of an object is determined by its motion speed. Without external force, its motion state will not change. This property of an object is called inertia. So Newton's first law is also called inertia law. The first law also clarifies the concept of force. It is clear that force is the interaction between objects, It is pointed out that force changes the motion state of an object. Because acceleration describes the change of the motion state of an object, force is related to acceleration rather than speed. If we don't pay attention to this point in our daily life, it is easy to produce illusion
Note: Newton's first law does not hold in all reference frames. In fact, it only holds in inertial reference frame. Therefore, whether Newton's first law holds or not is often regarded as the criterion of whether a reference frame is inertial reference frame
2. Newton's second law
Content: the object will produce acceleration under the action of combined external force. The direction of acceleration is the same as that of combined external force. The magnitude of acceleration is directly proportional to the magnitude of combined external force and inversely proportional to the inertial mass of the object
The second law quantificationally describes the effect of force and quantifies the inertia of an object. It is vector and instantaneous
It should be emphasized that the external force on the object will produce acceleration, which may change the motion state or speed of the object, but this change is related to the motion state of the object itself
In vacuum, because there is no air resistance and all kinds of objects are only subjected to gravity, they all have the same acceleration regardless of their mass. Therefore, when they fall freely, their velocity changes are the same in the same time interval
Newton's third law
Content: the force and reaction between two objects are equal in size and opposite in direction on the same straight line
Explanation: in order to change the motion state of an object, there must be other objects interacting with it. The interaction between objects is reflected by force. It also means that the action of force is mutual, and there must be reaction force if there is action. They act on the same straight line with equal size and opposite direction
It should also be noted that:
(1) Acting force and reaction force are not primary and secondary, successively. They produce and disappear at the same time
(2) This pair of forces act on different objects and cannot be counteracted
(3) Force and reaction must be forces of the same nature
(4) It has nothing to do with the frame of reference

What are the three laws of Newton?

Newton's three laws
Newton's three laws are important laws in mechanics, which are the basis of studying classical mechanics
1. Newton's first law
Content: any object remains stationary or moving in a straight line at a constant speed until it is forced to change this state by the force of other objects
Explanation: all objects have the tendency of keeping still and moving in a straight line at a constant speed. Therefore, the motion state of an object is determined by its motion speed. Without external force, its motion state will not change. This property of an object is called inertia. So Newton's first law is also called inertia law. The first law also clarifies the concept of force. It is clear that force is the interaction between objects, It is pointed out that force changes the motion state of an object. Because acceleration describes the change of the motion state of an object, force is related to acceleration rather than speed. If we don't pay attention to this point in our daily life, it is easy to produce illusion
Note: Newton's first law does not hold in all reference frames. In fact, it only holds in inertial reference frame. Therefore, whether Newton's first law holds or not is often regarded as the criterion of whether a reference frame is inertial reference frame
2. Newton's second law
Content: the object will produce acceleration under the action of combined external force. The direction of acceleration is the same as that of combined external force. The magnitude of acceleration is directly proportional to the magnitude of combined external force and inversely proportional to the inertial mass of the object
The second law quantificationally describes the effect of force and quantifies the inertia of an object. It is vector and instantaneous
It should be emphasized that the external force on the object will produce acceleration, which may change the motion state or speed of the object, but this change is related to the motion state of the object itself
In vacuum, because there is no air resistance and all kinds of objects are only subjected to gravity, they all have the same acceleration regardless of their mass. Therefore, when they fall freely, their velocity changes are the same in the same time interval
Newton's third law
Content: the force and reaction between two objects are equal in size and opposite in direction on the same straight line
Explanation: in order to change the motion state of an object, there must be other objects interacting with it. The interaction between objects is reflected by force. It also means that the action of force is mutual, and there must be reaction force if there is action. They act on the same straight line with equal size and opposite direction
It should also be noted that:
(1) Acting force and reaction force are not primary and secondary, successively. They produce and disappear at the same time
(2) This pair of forces act on different objects and cannot be counteracted
(3) Force and reaction must be forces of the same nature
(4) It has nothing to do with the frame of reference

What are Newton's three laws?

Newton's first law: when any body is not subject to any external force, (Fnet = 0) always maintains a state of uniform linear motion or static state until the external force acting on it forces it to change this state

All the formulas of physics compulsory one in senior high school?
For the liberal arts class

High school physics formula all physics theorem, law, formula table 1, particle motion (1) ---- linear motion 1) uniform variable speed linear motion 1. Average velocity VT = s / T (definition) 2. Useful inference vt2-vo2 = 2As 3. Middle time velocity VT / 2 = VT + VO / 2 4. Final velocity VT = VO + at 5

Seek high school physics compulsory one all formula! Thank you!

It is suggested that you write these / into fractions on paper: S = vcchu T + (at ^ 2) / 2 --- (T ^ 2 is the square of T), V end = vcchu + at --- (2), s level = vpping / T = (vmut-vcchu) / T --- (3) (the last one is only applicable to the uniform straight line), and get V end ^ 2 - V from formula (1) and (2)

High school physics compulsory formula summary, as long as the formula

1、 The motion of a particle (1) ---- linear motion 1) uniformly variable speed linear motion 1. Velocity VT = VO + at 2. Displacement S = VO + at & # 178 / 2 = vplane t = VT / 2T 3. Useful inference vt & # 178; - vo & # 178; = 2As 4. Average velocity vplane = s / T (definition) 5. Velocity VT / 2 = vplane = (VT + VO)

High school physics compulsory one of those formulas how to correctly use in the topic? I always can't use

In fact, there are three main problems in the derivation of the equation of uniform motion

The following statement about uniform variable speed linear motion is correct ()
A. The change of displacement in any same time is the same B. the change of velocity in any same time is the same C. The change of acceleration in any same time is the same D. the change of velocity at any time is the same

A. So a is wrong. B, the acceleration of uniform linear motion does not change. According to △ v = at, the change of velocity in the same time is the same. So B is right, C is wrong. D, the velocity of uniform linear motion changes uniformly. So D is wrong. So B

When a bus starts to move in a straight line with constant acceleration a, there is a passenger chasing the bus at a constant speed in the distance s behind the rear of the bus. It is known that the driver can see the farthest distance so from the front of the bus from the front mirror, and the driver can only notice the person if he can see the image of the person in the mirror, Only in this way can the bus be stopped. What is the expression of the condition that the passenger must satisfy in order to catch up with the bus?

The critical condition of passenger's forward VT is 1 / 2at2 (square) + S - vt = so. Because of a uniform speed and a uniform acceleration, their distance first decreases and then increases at a constant speed. So at T1, their distance decreases and then increases. At T2, their distance decreases and then increases again

How to deduce the effective value of sinusoidal AC voltage,

Suppose the AC voltage is u = u0sinwt, I = [U0 / R] sinwt, the thermal power at each instant is; DP = [U0 / R] 2 [sinwt] 2 * r, the heat generation in one cycle is; q = ∫ DP * DT = ∫ U0 / R] 2 [sinwt] 2 * RDT = [U0 / R] 2 * r ∫ [sinwt] 2DT = [U0 / R] 2 * r ∫ [1 / 2] [1-cos2wt] DT = [1 / 2] [U0 / R] 2 * r ∫ [1