The angle of contact, also known as the contact angle, is the angle formed by a liquid at the interface between two immiscible phases, such as a liquid and a solid or a liquid and a gas. It is the angle between the tangent to the liquid surface and the solid or gas surface at…
Surface tension is a property of liquids that arises due to the cohesive forces between the molecules at the surface of the liquid. In other words, it is the measure of the attractive force that holds the molecules of a liquid together at the surface. The molecules at the surface of a liquid experience an…
Surface energy refers to the energy required to increase the surface area of a material or object. It is a measure of the cohesive forces between the atoms or molecules in the bulk of the material and the surface atoms or molecules. The surface atoms or molecules have a higher potential energy than those in…
Buoyancy is a physical principle that describes the upward force exerted by a fluid (such as water or air) on an object that is partially or fully immersed in it. This force is equal to the weight of the displaced fluid and is known as the buoyant force. According to Archimedes’ principle, an object will…
Pascal’s law, also known as Pascal’s principle, is a fundamental principle in fluid mechanics that states that a change in pressure applied to an enclosed fluid is transmitted uniformly in all directions throughout the fluid, regardless of the shape or size of the container. In other words, if a pressure is applied to a fluid…
Pressure in a fluid is the force per unit area that the fluid exerts on the surface it comes in contact with. This pressure is a result of the motion and collisions of the individual particles of the fluid, such as molecules or atoms, and is described by the fluid’s properties, such as its density…
Escape velocity is the minimum velocity that an object needs to achieve in order to escape the gravitational pull of a celestial body, such as a planet, moon, or star, and move away from it into space. The escape velocity is calculated using the following formula: Ve = sqrt(2GM/r) Where: Ve = escape velocity G…
Satellites in circular orbits move around the Earth at a constant distance from the Earth’s center. This type of orbit is also known as a “geostationary orbit” or “geosynchronous orbit”. In this type of orbit, the satellite takes the same amount of time to complete one orbit as the Earth takes to complete one rotation…
The motion of planets can be explained by Kepler’s laws of planetary motion, which were derived by the German astronomer Johannes Kepler in the early 17th century based on observations made by the Danish astronomer Tycho Brahe. Kepler’s first law states that the orbit of a planet is an ellipse with the sun at one…
A geostationary orbit is a circular orbit around the Earth, with an altitude of approximately 35,786 km (22,236 miles), in which a satellite appears to remain stationary with respect to a fixed point on the Earth’s surface. This means that the satellite moves at the same rate as the Earth’s rotation, completing one orbit in…
