Mechanics

# Mechanics

It is clear that it is not enough to use only one measuring unit for a particular physical size. So offten, besides basic units, larger and smaller units of measure are introduced. To indicate these units, we use prefixes that...
If we select a measuring unit for each size, we get a system of measuring unit. Today we have a unique international system where for each size there is a precisely defined unit of measure. This is called International System...
Area The surface area represents a physical size of a body that is obtained by multiplying its length and width. Before calculating the surface area, it is necessary to measure the length and width of the rectangles. If it's a...
The simplest example of straight linear motion is the straight line movement at constant speed. A linear movement is a movement where the body travels equal lengths during the same amounts of time. Example: A car has passed the lengths...
In nature, we rarely encounter uniform movement. Usually, the bodies change the speed of movement during their movement. Before starting to move, the speed of the car is zero. At the beginning of the movement this speed increases. When approaching...

### History of Physics – Movement and Gravitational Interaction

Aristotle (384-322) studied many fields like philosophy and the natural sciences. Among other things, he studied the movement. He thought that the natural place of the air is up and the water was down. Although his theory is not...

### The Gravity Force, Weight, and The Center of Gravity

When we hold an item in our hand, it presses our hand downwards. The force by which the body presses the horizontal surface on which it stands is called the weight of the body. The gravity force and the weight...
If some body is being dropped, it will start falling down towards the Earth's surface. It has been determined experimentally that all bodies have the same speed if they fall through the space that has no air. Any two...
Gravitational Interaction   Gravity is an invisible force that draws all the bodies in the Universe to each other. Solar gravity keeps the planets in their orbits. Earth's gravity 'ensures' that the Moon circulates in its orbit around the Earth. The...

### Newton’s Third Law: The Law of Action and Reaction

Third Newton's law is often called the Law of Action and Reaction. And the law explains the nature of force between two interaction bodies that have equal magnitude and the opposite directions. If the force comes from one body and...