Сформулируйте вопросы на английском языке и дайте ответы на них. Какие типы взаимодействия существуют в природе? Опишите их природу. Укажите их радиус действия.
What kinds of interactionsexist in nature? Describe their nature. Define their radius of action.
There are four types of interaction:
1) gravitational
2) electromagnetic
3) strong
4) weak.
Gravitational interaction exists between objects with mass, electromagnetic interaction occurs when bodies are charged. These two interactions have very wide radius of action. Strong interaction occurs into the atom, weak – in the molecule.
Сформулируйте вопросы на английском языке и дайте ответы на них. Какое тело называется свободным? Что такое поле в физике? Что такое сила? Куда приложена сила тяжести, действующая на тело, и как она направлена?
Which body is called free? What is the field in physics? What is the force? Where lays the point of acting of gravity forces and where it is directed?
Body can be called free if there are no any forces which are acting on it.
Field is the special form of matter via which bodies interact with each other (gravitational field, electromagnetic field).
The force is any influence that causes an object to undergo a certain change, either concerning its movement, direction, or geometrical construction.
Point of acting of gravity force is called center of mass of that body. The force is directed to the center of Earth.
Сформулируйте вопросы на английском языке и дайте ответы на них. Какие силы в механике вы знаете? Сформулируйте законы Ньютона. Что такое инерциальная система отсчета?
What forces in mechanics do you know? Formulate the laws of Newton. What is inertial reference system?
In mechanics usually have to deal with three main types of forces: the force of gravity the elastic force and the friction force.
The force of gravity exerted on an object is equal to the product of its mass (a scalar quantity) and the free-fall acceleration: F=mg
Elastic force, it’s a force arising from the deformation of a solid body which depends only on the body's instantaneous deformation and not on its previous history, and which is conservative.
The friction force is a force that is created whenever two surfaces move or try to move across each other.
F=µN;
N=mg
Newton’s first law – In the absence of external forces, an object at rest remains at rest and an object in motion continues in motion with a constant velocity (that is, with a constant speed in a straight line); When no force acts on an object, the acceleration of the object is zero.
Newton’s second law of motion – the acceleration of an object is directly proportional to the resultant force acting on it; The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.
Newton’s
third law;
third law of motion; third principle of dynamics – if two objects
interact, the force
exerted by object 1 on object 2 is equal in magnitude to and opposite
in direction to the force
exerted by object 2 on object 1.
An inertial frame of reference is a frame of reference in which Newton's first law of motion applies: an object moves at a constant velocity unless acted on by an external force; and is one that is not accelerating.