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What causes an object to maintain its state of motion?

Galileo developed the concept of inertia in the 17th century. He is also responsible for the development of the concept of friction. Friction is the force that opposes inertia. In a world without friction, once an object is in motion, it would not stop until another force caused it to stop. A driver could start the engine on a car, accelerate to highway speed, kill the engine and coast to his destination without using any more energy, because the car is in motion. However, without the force of friction, acceleration, steering and braking, a traditional automobile becomes problematic.\nAccordin..

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What is a low-mass star?

Protostars are hard to see and study due to the amount of dust and gas surrounding them, so there is less known about them than other stars. These stars follow a similar pattern of life and death as other stars. Once they use up the fuel in their core, the core shrinks, which causes the atoms outside the core to shrink and speed up their fusion. This in turn makes the star brighter, but it also causes the star to grow its outer areas, turning it into a red giant.

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How does the sun work?

The hydrogen in the sun is in motion. The higher the temperature of the stellar plasma, the harder the atoms of hydrogen collide with each other. At the very high temperature of the sun's core, hydrogen collisions are too energetic for the mutual repulsion between the atoms' electron shells to resist each other, and they instead fuse into new atoms of helium. A single atom of helium has slightly less mass than two atoms of hydrogen. The difference in mass represents the matter that has been converted to energy by the fusion, a process described by Einstein's famous equation E = ..

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What do the numbers assigned to vertebrae signify?

The cervical spine has seven vertebrae, labeled from C1, which is nearest to the skull, to C7. These bones make up the neck and have the greatest range of motion of all vertebrae. The first and second cervical vertebrae allow a person to nod and turn his head from side to side, says the Mayfield Clinic.\nThe thoracic spine is below the cervical spine and has 12 vertebrae, T1 to T12. These vertebrae connect to the ribcage and have a more limited range of motion. The two lower sections of the spine have five vertebrae each. The lumbar spine consists of vertebrae L1 to L5, which are the largest v..

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What is the difference between metric and standard tools?

Standard American equivalent tools are usually referred to as standard tools or SAE tools. This system is based on imperial measurements, which means that all measurements and sizes are in inches.Metric tools use the metric system, as the name suggests. This means that all measurements and sizes are in millimeters or centimeters.Although there are two separate systems of measurement and sizing for tools, many tools incorporate both systems, which makes them universal. Many tool manufacturers produce tools for a variety of countries, and this keeps them from having to produce two different sets..

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What are the five phase changes of matter?

In the instance of a glass of water, the H20 is in a liquid state. As it heats up, the molecules become excited and move around a lot. Eventually, the water will become a gas. The physical conditions that are present cause the phase to change. Adding energy will cause the matter to increase in phase. For instance, a solid will become a liquid, liquid will become gas, etc. Adding energy will not cause it to revert to a lower phase. Removing energy from it will cause it to go from liquid to solid, for example. Water heating up and then hitting cooler air, such as on the outside of a glass, will ..

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How are molecular compounds formed?

The properties of a molecule are a result of the elements involved and the properties of the covalent bonds that hold them together. Covalent bonding occurs when atoms share electrons, which creates a bond that doesn't dissociate easily. The difference in electronegativity values between atoms determines the type of bond that is formed. If electronegativity values are very similar, a nonpolar covalent bond will form. If the difference in electronegativity values is significantly different but not greatly so, a polar covalent bond will form. The polar bonds in a molecule can add to the ove..

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How do lysosomes and vacuoles work together?

Matter used in the production of energy – such as starches, fat and glycogen – enter the cell via endocytosis. Vacuoles form by this pinching-off process from the cell's outer membrane. When the vacuole envelops the matter, it becomes an endosome. Surrounded by its own cellular membrane, endosomes store cellular materials until they are ready for processing by lysosomes.\nWhile the structure is produced by the Golgi body, the strong enzymes are produced by the endoplasmic reticulum. Approximately 50 different enzymes, known as acid hydrolases, break down proteins, genetic materials, p..

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How often do oak trees produce acorns?

Attempts have been made to try and predict mast years, and records have been kept of when they have occurred in many species of trees throughout Europe. It is hoped that a potential trigger for mast crops may be discovered, although as yet none has been found.

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What are some of the effects of high cortisol levels?

Cortisol is a steroid hormone produced within the cortex of the adrenal gland as a reaction to stress or a decrease in blood sugar levels. Prolonged elevated cortisol levels can result in a wasting away of muscle tissue and progressive bone disease. Increased cortisol levels, and the stress that triggers it, can have a debilitating effect on the body's immune system. As a result, otherwise healthy adults can experience a significantly longer period of time for a wound to heal than individuals whose immune systems have not been affected by prolonged stress or elevated cortisol levels.Some ..

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