MindMap Gallery Newton's Laws of Motion Study Notes
This is a study note about Newton's laws of motion in college physics. It tells about several common forces, three laws, Kepler's three laws, inertial and non-inertial systems.
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Avatar 3 centers on the Sully family, showcasing the internal rift caused by the sacrifice of their eldest son, and their alliance with other tribes on Pandora against the external conflict of the Ashbringers, who adhere to the philosophy of fire and are allied with humans. It explores the grand themes of family, faith, and survival.
This article discusses the Easter eggs and homages in Zootopia 2 that you may have discovered. The main content includes: character and archetype Easter eggs, cinematic universe crossover Easter eggs, animal ecology and behavior references, symbol and metaphor Easter eggs, social satire and brand allusions, and emotional storylines and sequel foreshadowing.
[Zootopia Character Relationship Chart] The idealistic rabbit police officer Judy and the cynical fox conman Nick form a charmingly contrasting duo, rising from street hustlers to become Zootopia police officers!
Newton's laws of motion
Several common forces
gravity
Definition: There is a force of attraction between any object with mass.
The law of universal gravitation: Two particles with a certain mass attract each other along the line connecting them. The magnitude of the attraction is directly proportional to the product of the masses of the two particles and inversely proportional to the square of the distance between them.
formula:
Applicable conditions: The law of universal gravitation only applies to the interaction between two matter points.
Gravity is the component of gravity
formula:
Elasticity
Definition: The force generated by objects deforming due to contact with each other. Including the elastic force of the spring, the positive pressure and the tension of the rope.
formula:
Friction
static friction
Definition: When two objects in contact remain relatively stationary with each other and have a tendency to move relative to each other along the contact surface, a pair of forces will be generated between the contact surfaces to prevent the above movement trend.
formula:
sliding friction
Definition: When two objects are in contact with each other and slide relative to each other, the interactive force that occurs at the point of contact between the two objects hinders the movement of the objects.
formula:
fluid resistance
Definition: When an object is in a fluid (liquid or gas) and moves relative to the fluid, the object will experience resistance from the fluid.
When the relative speed is small:
When the relative velocity is large:
Terminal velocity: Fluid resistance increases with speed. When balanced with gravity, the object will fall at a constant speed at the terminal velocity.
Surface Tension
Definition: The force between various parts of the liquid surface that pulls each other tightly. The direction is along the liquid surface and perpendicular to the boundary line of the liquid surface.
four fundamental forces of nature
Kepler's three laws
First Law: The trajectories of all planets around the sun are ellipses, and the sun is at one focus of all ellipses.
Second Law: For each planet, the line joining the Sun and the planet sweeps out the same area in equal times.
For each planet, the area swept out by the line connecting the Sun and the planet in equal amounts of time
Third Law: The square of the period of a planet's revolution is proportional to the cube of its orbital radius.
Problem solving steps
1. Determine the force analysis of the object
2. Establish a coordinate system
3. Make equations
4. Complementary equations
5. Solve with symbols first and then data
Inertial and non-inertial frames
Inertia: It is the characteristic of any object to remain stationary or move in a straight line at a uniform speed.
The so-called core competencies are a special set of knowledge systems. Every position requires core competencies, There is no need to match knowledge; core competencies are important to everyone, and some people don’t recognize the knowledge.
Inertial reference frame: A frame of reference defined by Newton's first law in which an object without a force will remain at rest or move in a straight line at a uniform speed.
Non-inertial frame: All reference frames that undergo accelerated motion (i.e. have acceleration).
inertial force
Definition: A force that is different from gravity, elasticity, pressure and tension, etc. It has no force exerting object and no reaction force. It is a virtual force.
1. Inertial force in the translational acceleration reference frame:
2. Inertial force (inertial centrifugal force) in a uniformly rotating reference frame:
3. Coriolis force: In a rotating non-inertial system, the Coriolis force must be introduced before Newton's law can be used.
Angular velocity vector direction: The four fingers rotate in the direction of the object, and the thumb points to the angular velocity direction.
three laws
Applicable conditions: constant quality, low speed
First Law (Law of Inertia)
Definition: Any object remains at rest or moving in a straight line at a uniform speed until a force forces it to change this state.
formula:
second law
Definition: When an object is acted upon by an external force, the magnitude of the acceleration obtained by an object is proportional to the external force and inversely proportional to the mass of the object; the direction of the acceleration is the same as the direction of the vector sum of the external force.
formula:
Applicable conditions
1. Newton’s second law only applies to particles.
2. There is an instantaneous relationship between the net external force and acceleration.
The principle of superposition of forces: When several external forces act on an object at the same time, the acceleration produced by the combined external force is the same as the vector sum of the acceleration produced by each external force.
third law
Definition: Object A acts on object B with force Fab, and object B must act on A with force Fba at the same time. The two forces act on the same straight line, and are equal in magnitude and opposite in direction.
formula:
Action and reaction forces
1. They always appear in pairs, rising and dying together. There is a one-to-one correspondence between them.
2. They act on two objects respectively and are by no means a balancing force.
Wholeness and interrelationships
1. Newton's first law reveals inertia, establishes the inertial reference system, and provides conditions for the establishment of the second law.
2. Newton’s third law enables us to move from studying single particles to studying interacting composite systems.
3. None of the three major laws puts forward special requirements for force, and no specific numerical value can be obtained.