Utilisateur
(B) Geology is the study of the formation and composition of the earth. The study of all the living things on the earth is biology. The study of the earth as part of the universe is earth science. The study of fossilized deposits is paleontology.
(D) The three major types of rocks are sedimentary, metamorphic, and igneous.
(A) The relatively thin outer layer of the earth is called the crust, which rides on the mantle, which is heated by the molten metal in the core.
(B) The earth is about 4.54 billion years old as determined by measuring half-lives of radioactive minerals. Erosion studies are not reliable over long time periods, because those rates can and do change over the course of time and from place to place. Carbon
(C) Salt and gypsum are characteristic examples of chemical sedimentary rocks.
(C) Biology is the study of living things. The study of plants is botany. The study of animals is zoology. The study of minerals is minerology, which is a subset of geology.
8. (C) Animal cells sometimes have flagella, which are threadlike structures that function in the movement of simple organisms and the movement of particles in more complex organisms.
(A) The cell is the basic structural and functional unit of virtually all life-forms.
(C) Carbohydrates are composed of carbon, hydrogen, and oxygen.
(B) Genes carry hereditary traits from parents to their offspring.
(B) Vertebrates are animals whose primary defining characteristic is that they have a spine or backbone. This spine or backbone is made of bone or cartilage. Invertebrates do not have a spine or backbone. Only a small group of vertebrates walk upright. For example, humans do. However, lizards, whales, and horses-which are all vertebrates— do not walk upright. Having an enclosed circulatory system is not the primary defining characteristic of vertebrates.
(A) In humans, the endocrine system includes glands that regulate growth and blood pressure. The lymphatic system brings oxygen to cells and removes waste products
(D) Diseases can be divided into two categories, infectious and noninfectious.
(B) The law of independent assortment, as postulated by Gregor Mendel, says that each trait is inherited independently of other traits.
(A) There are four major oceans on the earth that together hold about 96 percent of the planet's water. The four major oceans are the Pacific, Atlantic, Indian, and Arctic.
(D) Subduction zones are areas where tectonic plates meet.
(B) False. Although it is true that the deepest marine zones have no plants, they contain only a limited variety of animal life, not a surprising variety of marine animals.
(D) Tides are caused by the gravitational pull of the sun and the moon on the freely moving waters of the earth. Since the moon is much closer than the sun, the moons influence is greater. However, the sun still has an effect on earth's waters.
(A) An ocean can be divided into seabed, water, and shoreline. The continental shelf and underwater canyons are part of the seabed.
1. (A) The earth is part of a solar system that contains the sun and seven other planets and an asteroid belt. Pluto is no longer classified as a planet. So the solar system consists of the sun, the earth, and seven other planets.
(B) The rotation of the earth on its axis causes day and night. Tides are caused by the gravitational pull of the sun and earth's moon. The seasons are caused by the tilt of the earth's axis, which brings parts of the earth closer to the sun at different times of the year. The rotation of the earth around its axis does not cause the tilt of the earth's axis.
(C) The earth's axial tilt causes the seasons.
(C) The asteroid belt is between Mars and Jupiter.
(D) The smallest planet in the solar system is Mercury, and the largest body in the solar system is the sun. Jupiter is the largest planet. However, since the sun is about 10 times larger than Jupiter, the sun is the largest body in the solar system, Note that Pluto is no longer classified as a planet. Therefore, it cannot be the smallest planet in the solar system.
. (B) Light travels at an approximate speed of 186,000 miles per second.
(A) The barometric pressure at a particular location directly depends on the air's temperature and humidity. Solar flares and wind speed have nothing to do with barometric pressure.
(D) Climate is the average of the weather conditions in a certain place over time.
(A) Humidity refers to the amount of moisture in the air.
(B) Winds are directly caused by differences in air pressure that seek to equalize themselves.
(D) Cumulus clouds are typically found at lower atmospheric levels. Stratus, cumulus, and stratocumulus clouds occur at altitudes of 6,000 feet (1,829 mi) or less. Cirrus, cir-rostratus, and cirrocumulus clouds are delicate, wispy clouds at altitudes above 20,000 feet (6,096 mi). Altostratus, altocumulus, and nimbostratus clouds are typically found between 6,000 and 20,000 feet (1,829-6,096 mi).
(B) Matter is anything that occupies space and has mass. Matter does not have to maintain a specific size or shape-liquids don't. Matter also does not have to maintain a definite volume gases don't.
(A) Inertia is the property of matter to resist a change of position or motion. This is addressed by Newton's first law of motion, which states that an object at rest stays at rest and an object in motion stays in motion (at the same speed and in the same direc-tion) unless acted on by an unbalanced force.
(B) Matter exists in one of three states or conditions: solid, liquid, or gas. Frequently, a substances state may be changed by adding or removing heat, such as when heat melts ice into liquid water and then turns that ice into steam. More recent, higher-level texts add a fourth state of matter-plasma-which is different from a gas because plasma is electrically conductive. However, plasma is unlikely to be addressed in an ASVAB
(A) The density of a substance is the relationship of its mass to a unit of volume.
Density is determined by dividing the substance's mass by its volume. For any particular substance, there's a linear relationship between its mass and its volume: when one increases, so does the other, and vice versa.
(C) A chemical change is always accompanied by the release or absorption of energy. A chemical change involves a change in the substance's chemical makeup. Some examples are burning wood, an egg cooking, iron rusting, and food rotting. In all of these cases, heat is involved. The substance resulting from the process cannot be turned back into the original substance.
(B) A chemical equation shows a chemical change and must balance. A chemical change results in either a new chemical compound or the separation of a compound into its elements. The total quantities to the left of the arrow must equal the total quantities to the right of the arrow.
2. (A) The Periodic Table is used to present all the elements in a way that shows their similarities and differences. The elements are arranged in order of increasing atomic number.
(A) The atomic number of the element carbon is 6. The chemical symbol for carbon is
C. In the version of the periodic table provided in this book, the atomic number of an element is located just above and to the left of the symbol for the element. Note that
C) The blocks of elements between groups Il and IT on the Pertodic Tuble ar bo transition metals Lanthanides and actinides, shown in the two separate row bees the main part of the Periodic Table, would it into group 3 and are also considered ne sition metals. However, the question asked about the entire block of elements bets groups Il and III.
(B) The atomic mass of potassium is 39.098. To find the answer, go to potassium's bi in the Periodic Table (symbol K) and look at the number at the bottom of the block
A) The number of protons in an atom's nucleus determines the element's atoms number.
(C) A solution is a mixture of one substance completely dissolved in another substa
(C) An atom has the same number of protons and electrons.
(D) On the basis of their atomic structure, atoms are considered metals if they lend electrons and nonmetals if they borrow electrons. The periodic table is organized so that elements with similar chemical and physical properties are aligned in columns or groups. Metals, which are found on the left two-thirds of the periodic table, tend to form compounds by losing or lending electrons.
(B) The unit of length called the angstrom (A) is useful for measuring the wavelength of light and equals 10® cm (or 0.00000001 cm) or 10-10 m (0.0000000001 m).
A) An atom with the same number of protons but a different number of neutrons than other atoms of the same element is an isotope of that element.
. (A) Potential energy is due to the position of an object, and kinetic energy is the energy of motion.
(A) A boulder perched precariously at the edge of a long, steep downslope on a mountainside is said to have potential energy. If whatever is propping up the boulder gives way and the boulder rolls down the slope, the boulder will have kinetic energy as it moves downhill.
1. (B) About 50 percent of the earth's outer layer-including the seas, oceans, and atmosphere-is made of oxygen. Oxygen is the most abundant element in the universe to our knowledge. Most of the oxygen in the earth's crust is in the form of silicates. These are minerals composed of oxygen, silicon (which is the second most abundant element in the earth's crust), and other elements. Some examples of silicates are mica, feldspar, and quartz.
(A) When evaporation and condensation take place at the same rate, this is equilibrium.
Equilibrium is a balanced state.
(C) In chemical reactions, water forms compounds that are classified as bases or acids.
Pure water is considered neutral, with a pH of 7. Water acts as an acid (i.e., donates hydrogen atoms) when it reacts with a stronger base, such as sodium hydroxide. Water acts as a base (i.e., accepts hydrogen atoms) when it reacts with a stronger acid, such as hydrochloric acid.
4. (A) Metal oxides
. (B) The four types of chemical reactions are combination, decomposition, single replacement, and double replacement.
(B) A pulley is used to move heavy objects in a vertical direction.
(D) A seesaw is an example of a lever. Specifically, a seesaw is an example of a first-class lever, where the fulcrum is placed between the applied force and the load. Which end has the load and which end has the applied force changes as each person alternates using his or her legs to push off from the ground.
(A) A cylinder with a narrow inclined plane wrapped around it is a description of a
SCTE.
4. (B) When a lever is balanced on its fulcrum, the force on one arm matches the force on the other. This system is in equilibrium. If a load is placed onto one end of such a lever but not onto the other end, the balance is upset. The lever will tilt to the side with the load on it (think of one person on a seesaw). If we lift the load (the person gets off the seesaw) or apply a similar load to the other end of the lever (think of the second person getting onto the seesaw), the system becomes balanced again.
(B) A doorknob is an example of a wheel and axle. This is a wheel rigidly attached to an axle; the ade turns when the wheel is turned.
(D) If a 5-newton force (Force 1) is directly opposed to a 7-newton force (Force 2), the resultant force will be a 2-newton force in the direction of Force 2. In this problem, you should subtract the smaller force from the larger force since the forces are diametrically opposed.
C) Bernoulli's principle states that an increase in the speed of a fluid over an object occurs simultaneously with a decrease in the fluid's pressure on that object.
(B) When they are heated, most solids, liquids, and gases expand (increase in volume).
Increased heat causes the substance's atoms to vibrate faster, thereby increasing the space between them and increasing the volume of the substance.
(D) The three methods of heat transfer are radiation, conduction, and convection. The first method, radiation, occurs when electromagnetic waves emitting from a source carry heat energy away from that source to a distant object. (Note that this radiation has nothing to do with nuclear energy.) The second method, conduction, is the transfer of heat between atoms as they collide within a substance. Conduction is usually the most efficient method for heat transfer in solids. The third method, convection, involves a fluid (such as a liquid or air) being heated. That fluid then expands and travels away from the heat source, typically displacing other parts of the fluid. Those other parts of the fluid then move toward the source and get heated. This process continues as the
(A) A diesel engine is an example of an internal combustion engine. A diesel engine gets its energy from the combustion of a fuel and an oxidizer (air) in a combustion chamber. The expansion of the high-pressure, high-temperature gases produced by this combustion applies direct force to the appropriate engine component to fulfill the engine's purpose.
(A) A liquid has definite volume and takes the shape of its container.
C) The speed of a wave is equal to the frequency of the wave multiplied by the wavelength. This equation, known as the wave equation, shows the mathematical relationship between the speed of a wave (v), and its wavelength (2), and frequency (f).
Using the symbols v, 2 and f, the equation can be rewritten as
v =f•2
2. (A) Sound waves are longitudinal waves in solids, liquids, or gases. Sound waves in solids can also be transverse waves (waves that oscillate perpendicularly to the direction of propagation).
3. (B) Wave motion is a method of transferring energy by means of a distortion. In wave motion, the distortion travels away from the place where it was produced in the medium.
(B) Light traveling toward a reflective surface is called incident light.
(A) A convex lens converges light. On the other hand, a concave lens diverges the refracted rays so that they appear to come from one point, called the principal focus.
(D) Refraction happens when light waves are bent passing from one material into another:
(A) Almost all the mass of an atom is concentrated in the nucleus. Protons and neutrons are found in the nucleus of an atom. Of the three types of subatomic particles, protons and neutrons are significantly heavier than electrons.
2. (D) Direct current (DC) is a flow of electric charge in one direction at a constant rate.
In systems using alternating current (AC), the electric charge's direction of movement periodically reverses direction.
(B) When a neutral object is charged, it usually acquires the same kind of charge as that of the charged object it touches. Negatively charged objects have an excess of electrons, which seek to disperse themselves by hopping to the neutral object. As a result, the formerly neutral object is now negatively charged. Positively charged objects have an excess of protons and thereby attract electrons from the neutral object. This results in the formerly neutral object now having an overabundance of protons and being positively charged.
4. (B) According to Coulomb's law, particles with the same charge repel each other. Also known as Coulomb's inverse-square law, it was discovered by French physicist Charles-Augustin de Coulomb and was first published in 1784. Subsequent extensive tests have invariably found the law to be true.
(D) A primary cell is a voltaic cell whose electrodes are irreversibly consumed when the cell is used. On the other hand, a secondary (rechargeable) cell forms an insoluble product that sticks to the electrodes. A secondary cell can be recharged by applying an electrical potential in the reverse direction, temporarily converting the cell from a galvanic cell to an electrolytic cell.