Category: Physics

What is the economic impact of coal? These include the direct employment of nearly 150,000 people and the creation of 3.3 jobs for every job in coal mining, for a total of more than 500,000 jobs. Coal generated $26 billion in sales and paid $13 billion in direct wages and salaries according to 2016 analysis […]

What is a geologic gap? A gap is a geological formation that is a low point or opening between hills or mountains or in a ridge or mountain range. It may be called a col, notch, pass, saddle, water gap, or wind gap, and geomorphologically is most often carved by water erosion from a freshet, […]

Does air expand when its hot? As the molecules heat and move faster, they are moving apart. So air, like most other substances, expands when heated and contracts when cooled. Because there is more space between the molecules, the air is less dense than the surrounding matter and the hot air floats upward. Do inert […]

What are the 4 types of touch receptors? The four major types of tactile mechanoreceptors include: Merkel’s disks, Meissner’s corpuscles, Ruffini endings, and Pacinian corpuscles. Merkel’s disk are slow-adapting, unencapsulated nerve endings that respond to light touch; they are present in the upper layers of skin that has hair or is glabrous. What are the […]

How far up do balloons go? Toy balloons burst at around 10km, while professional meteorological balloons reach heights of 30km. The ultimate limit is set by Archimedes’s Principle, which says balloons will stop rising once their density matches the surrounding air. So there’s no chance of balloons entering the vacuum of space. Where do balloons […]

Are CFCs banned in India? India has successfully achieved the complete phase out of Hydrochlorofluorocarbon (HCFC)-141 b, which is a chemical used by foam manufacturing enterprises and one of the most potent ozone depleting chemical after Chlorofluorocarbons (CFCs) . Is CFC still used in India? Thanavat Junchaya, UNEP’s regional network coordinator for its CFC project, […]

What type of waves can the human eye detect? The human eye can detect the visible spectrum of the electromagnetic spectrum — a range of wavelengths between 390 to 700 nanometers. This is why scientists have always assumed that infrared light, a type of electromagnetic radiation with longer wavelengths than visible light, has been “invisible” […]

Why should you run towards a train? Being behind the locomotive when it hits the car is the safest place to be in crash. That is why so important that you (and your passengers) run far enough away from the tracks and in the direction of the oncoming train so you will not be hit […]

Which lines must be parallel? If two lines are cut by a transversal and corresponding angles are congruent, then the lines are parallel. Which line is a transversal? Definition: A line that cuts across two or more (usually parallel) lines. In the figure below, the line AB is a transversal. It cuts across the parallel […]

What do Venus Earth and Mars have in common? Venus, Mars and Earth, three out of the four inner or ‘rocky’ planets of the Solar System, have a lot in common – a solid surface you could walk on, a comparable surface composition, an atmosphere and a weather system. What planets can you walk on? […]