HighFour General Sciences Category C: Grades 9 – 10 Round 3 Wednesday, November 16, 2016 The use of calculator is not required. Answer #1 Explanation: Answer #2 Explanation: Answer #3 Explanation: Answer #4 Explanation: C A parsec (symbol: pc) is a unit of length used to measure large distances to objects outside our Solar System. One parsec is the distance at which one astronomical unit subtends an angle of one arcsecond. A parsec is equal to about 3.26 light-­‐years (31 trillion kilometers) in length. A The hertz (symbol Hz) is the unit of frequency in the International System of Units (SI) and is defined as one cycle per second. It is named for Heinrich Rudolf Hertz, the first person to provide conclusive proof of the existence of electromagnetic waves. B The joule, symbol J, is a derived unit of energy in the International System of Units. It is equal to the energy transferred (or work done) to an object when a force of one newton acts on that object in the direction of its motion through a distance of one meter (1 newton meter). D William Sturgeon (22 May 1783 – 4 December 1850) was an English physicist and inventor who made the first electromagnets, and invented the first practical English electric motor. The first artificial electromagnet, invented by Sturgeon in 1824. HighFour General Sciences Category C: Grades 9 – 10 Round 3 Wednesday, November 16, 2016 The use of calculator is not required. Answer #5 Explanation: Answer #6 Explanation: Answer #7 Explanation: Answer #8 Explanation: D The blastula (from Greek blastos, meaning "sprout") is a hollow sphere of cells, referred to as blastomeres, surrounding an inner fluid-­‐filled cavity called the blastocoele formed during an early stage of embryonic development in animals. A Generally, tribology includes three key topics: friction, wear and lubrication. Friction is the resistance to relative motion, wear is the loss of material due to that motion, and lubrication is the use of a fluid (or in some cases a solid) to minimize friction and wear. C Cold fusion is a hypothesized type of nuclear reaction that would occur at, or near, room temperature. This is compared with the "hot" fusion which takes place naturally within stars, under immense pressure and at temperatures of millions of degrees, and distinguished from muon-­‐catalyzed fusion. D The photoelectric effect or photoemission (given by Albert Einstein) is the production of electrons or other free carriers when light is shone onto a material. Electrons emitted in this manner can be called photoelectrons. HighFour General Sciences Category C: Grades 9 – 10 Round 3 Wednesday, November 16, 2016 The use of calculator is not required. Answer #9 Explanation: Answer #10 Explanation: Answer #11 Explanation: Answer #12 Explanation: C Lava is the molten rock expelled by a volcano during an eruption. The resulting rock after solidification and cooling is also called lava. The molten rock is formed in the interior of some planets, including Earth, and some of their satellites. C Stoichiometry is the calculation of relative quantities of reactants and products in chemical reactions. It is founded on the law of conservation of mass where the total mass of the reactants equals the total mass of the products leading to the insight that the relations among quantities of reactants and product typically form a ratio of positive integers. A The doldrums is a colloquial expression derived from historical maritime usage, which refers to those parts of the Atlantic Ocean and the Pacific Ocean affected by the Intertropical Convergence Zone, a low-­‐pressure area around the equator where the prevailing winds are calm. A The Oort Cloud is an extended shell of icy objects that exist in the outermost reaches of the solar system. It is named after astronomer Jan Oort, who first theorised its existence. The Oort Cloud is roughly spherical, and is thought to be the origin of most of the long-­‐period comets that have been observed. HighFour General Sciences Category C: Grades 9 – 10 Round 3 Wednesday, November 16, 2016 The use of calculator is not required. Answer #13 Explanation: Answer#14 Explanation: Answer #15 Explanation: Answer #16 Explanation: A The Hertzsprung-­‐Russell diagram (HR diagram) is one of the most important tools in the study of stellar evolution. Developed independently in the early 1900s by Ejnar Hertzsprung and Henry Norris Russell, it plots the temperature of stars against their luminosity (the theoretical HR diagram), or the color of stars (or spectral type) against their absolute magnitude (the observational HR diagram, also known as a color-­‐magnitude diagram). B A breeder reactor is a nuclear reactor that generates more fissile material than it consumes. These devices achieve this because their neutron economy is high enough to breed more fissile fuel than they use from fertile material, such as uranium-­‐238 or thorium-­‐232. D A cotyledon is a significant part of the embryo within the seed of a plant. Upon germination, the cotyledon usually becomes the embryonic first leaves of a seedling. The number of cotyledons present is one characteristic used by botanists to classify the flowering plants (angiosperms). D Radioactive decay (also known as nuclear decay or radioactivity) is the process by which the nucleus of an unstable atom loses energy by emitting radiation, including alpha particles, beta particles, gamma rays, and conversion electrons. A material that spontaneously emits such radiation is considered radioactive. HighFour General Sciences Category C: Grades 9 – 10 Round 3 Wednesday, November 16, 2016 The use of calculator is not required. Answer #17 Explanation: Answer #18 Explanation: Answer #19 Explanation: Answer #20 Explanation: C The Baily's beads effect is a feature of total solar eclipses. As the moon "grazes" by the Sun during a solar eclipse, the rugged lunar limb topography allows beads of sunlight to shine through in some places, and not in others. B Given m = 1000 kg and v = 100 m/s, we can use the formula potential energy = mgh but since height is not given, we use the formula for kinetic energy (in terms of m and v) since the kinetic energy is just equal to the potential energy: 1
1
𝑘𝑖𝑛𝑒𝑡𝑖𝑐 𝑒𝑛𝑒𝑟𝑔𝑦 = 𝑚𝑣 0 = 1000𝑘𝑔 100𝑚/𝑠
2
2
= 5,000,000 𝐽𝑜𝑢𝑙𝑒𝑠 D White blood cells (WBCs), also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from multipotent cells in the bone marrow known as hematopoietic stem cells. D Evolution is the change in the genetic composition of a population during successive generations, often resulting in the development of new species. The mechanisms of evolution include natural selection acting on the genetic variation among individuals, mutation, migration, and genetic drift.