Viscosity is normally independent of pressure, but liquids under extreme pressure often experience an increase in viscosity. The viscosity of gases increases as temperature increases and is approximately proportional to the square root of temperature.

The three factors that influence the viscosity of a lava are temperature, the dissolved gases it contains, and its chemical composition.

The viscosity of magma depends upon its silica content and temperature.

High viscosity lavas flow slowly and typically cover small areas. In contrast, low viscosity magmas flow more rapidly and form lava flows that cover thousands of square kilometers.

Question: Which of the following does not affect the viscosity of magma? Temperature Silica Content Amount of gas None of these affects the viscosity of the magma.

As temperature increases, viscosity and surface tension decrease because the raise in temperature speeds up the molecules and the movement makes the liquid move faster so the viscosity decreases.

In general, liquids tend to get “thinner” when their temperature increases. For example, honey and oil tend to flow better at higher temperatures. Therefore, increasing temperature decreases viscosity.

With an increase in temperature, there is typically an increase in the molecular interchange as molecules move faster in higher temperatures. With high temperatures, viscosity increases in gases and decreases in liquids, the drag force will do the same. …

Viscosity generally increases as the temperature decreases. The viscosity of a liquid is related to the ease with which the molecules can move with respect to one another.

Viscosity of water Water has a viscosity of 0.0091 poise at 25 °C, or 1 centipoise at 20 °C. As a function of temperature T (K): (Pa·s) = A × 10B/(T−C) where A=2.414 × 10−5 Pa·s ; B = 247.8 K ; and C = 140 K .

Dynamic viscosity is the resistance to movement of one layer of a fluid over another and is defined by Formula F7. 8. Kinematic viscosity is dynamic viscosity divided by density (Formula F7. 9) and is the ratio of viscous forces to inertia forces.

Common Units

The unit of viscosity is newton-second per square metre, which is usually expressed as pascal-second in SI units.

One of the most viscous liquids known is pitch, also known as bitumen, asphalt, or tar. Demonstrating its flow and measuring its viscosity is the subject of the longest continuously running scientific experiment, begun in 1927 at the University of Queensland in Australia.

A centipoise is one hundredth of a poise, or one millipascal-second (mPa⋅s) in SI units (1 cP = 10−3 Pa⋅s = 1 mPa⋅s). The CGS symbol for the centipoise is cP….Poise (unit)

Or, η = [M1 L1 T-2] × [M0 L2 T0]-1 × [M0 L1 T-1]-1 × [M0 L1 T0] = [M1 L-1 T-1]. Therefore, viscosity is dimensionally represented as [M1 L-1 T-1].

The SI unit of η is Newton-second per square meter (Ns. m^ – 2) or. Pascal-seconds (Pa .s) Hence the coefficient of viscosity is a measure of the resistance of the fluid to deformation at a given rate due to internal friction.

A magma’s viscosity is largely controlled by its temperature, composition, and gas content (see downloadable programs at the bottom of this page). The effect of temperature on viscosity is intuitive. Like most liquids, the higher the temperature, the more fluid a substance becomes, thus lowering its viscosity.

rhyolitic magma

Although there are several factors triggering a volcanic eruption, three predominate: the buoyancy of the magma, the pressure from the exsolved gases in the magma and the injection of a new batch of magma into an already filled magma chamber.

volcanic eruptions

There are two types of eruptions in terms of activity, explosive eruptions and effusive eruptions. Explosive eruptions are characterized by gas-driven explosions that propels magma and tephra.

Volcanologists can predict eruptions—if they have a thorough understanding of a volcano’s eruptive history, if they can install the proper instrumentation on a volcano well in advance of an eruption, and if they can continuously monitor and adequately interpret data coming from that equipment.

Volcanoes have several shapes, which are controlled by the composition of the magma and the nature of its eruption. If a volcano produces very fluid lava (low in the compound SiO2, or silica), the magma flows a long distance before it cools, making a flat, shield-shaped volcano.

Top 10 most explosive volcanic eruptions*

• Whakamaru.
• Taupo.
• Cerro Galán.
• Yellowstone Creek. Volume of erupted tephra: 1,000km3.
• Long Valley Caldera. Volume of erupted tephra: 580km3.
• Tambora. Volume of erupted tephra: 160km3.
• Crater Lake. Volume of erupted tephra: 50km3.
• Krakatoa. Volume of erupted tephra: 25km3.

The 10 Happiest Countries in the World

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2. Denmark. Denmark remained in the number two spot this year.
3. Switzerland.
4. Iceland.
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7. Sweden.
8. Luxembourg.

Price of Travel’s Asia Backpacker Index for 2020

• 1 – Hanoi, Vietnam (cheapest)
• 2 – Ho Chi Minh City, Vietnam.
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The Netherlands has been recognized as the best country in the world for its citizens to live, according to the CEOWORLD magazine 2020 report, while Germany and New Zealand placed second and third, respectively.

Best Countries to Live in The World

• Canada. Sitting high up near the pole is a massive stretch of land that makes the cold country of Canada.
• Finland.
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