Сформулируйте вопросы на английском языке и дайте ответы на них. Что является естественным спутником Земли? Какова природа гравитационных сил? Какова природа электромагнитных сил?
What is the natural satellite of the Earth?
The natural satellite of the Earth is the Moon.
What is nature of gravitational forces?
Any object (particle) with mass has a gravitational field around it.
What is the nature of electromagnetic forces?
Any charged object (particle) has an electromagnetic field around it.
Сформулируйте вопросы на английском языке и дайте ответы на них. Как вычисляется плотность тела, если известны его масса и объем? Что является причиной движения тел?
How can we calculate a density of the body, if we know mass and volume of that body?
To calculate a density of given body we need to divide mass by volume.
What is the reason of motion?
Motion is the result of an unbalanced force. Body motion can only occur in relation to other bodies and related spaces.
Сформулируйте вопросы на английском языке и дайте ответы на них. Какое взаимодействие ответственно за превращение элементарных частиц? Какие геометрические фигуры вы знаете? Опишите их.
Which interaction is responsible for the transformation of particles? Weak interaction is responsible foe the transformation of particles. Which geometrical shapes do you know?
Polygon – a plane figure that is bounded by a finite chain of straight line segments closing in a loop to form a closed chain or circuit. These segments are called its edges or sides, and the points where two edges meet are the polygon's vertices (singular: vertex) or corners.
Triangle a polygon with three corners or vertices and three sides or edges which are line segments.
Parallelogram is a simple quadrilateral (четырёхугольник) with two pairs of parallel sides. The opposite or facing sides of a parallelogram are of equal length and the opposite angles of a parallelogram are of equal measure.
Circle is the set of all points in a plane that are at a given distance from a given point, the centre. The distance between any of the points and the centre is called the radius.
Сформулируйте вопросы на английском языке и дайте ответы на них. Как отсчитывается угол поворота частицы при равномерном движении по окружности? Можно ли сравнивать величины разной размерности? Приведите примеры.
1.How can we measure the rotation angle of particle in uniform circular motion? Can we compare values of different dimensions? Give an example.
Let a material point moves in a circle of radius R. We introduce a Cartesian coordinate system whose origin is compatible with the center of the circle (Fig. 74). Position of a point on the circle is uniquely determined by the angle φ between the X axis and the radius vector of the point.
рис. 74
Cartesian coordinates of the point can be uniquely expressed through the angle formulas:
When the coordinate points of its movement, i.e. the rotation angle is changed, becomes a function of time. Therefore, the law of motion in this case represented by the function φ (t), that is, depending on the angle of rotation from time to time.
By analogy, we introduce the concept of a one-dimensional movement of the angular velocity.
Angular velocity ω is the ratio of the rotation angle to the length of time during which this change occurs, during the time interval tends to zero:
The unit of the angular velocity is rad / s - radians per second, but since radians is dimensionless, the dimension of the angular velocity can be simply 1 / c = 1 - a second power minus one.
2. We can’t compare values of different dimensions, for example 1 meter and 1 foot, or 1 degree and 1 radian. We need to convert feet to meter and find out that 1 foot =0.3048 m, and 1 radian≈57.324 degrees.