HS Sample Set 2, Round 7 from NSB
Find the number of degrees in the angle of elevation of the Sun when a 10-foot vertical flag pole casts a 10-foot shadow on level ground.
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Find the largest possible real range of the function $y = 1 - 2e^{\frac{x}{2} - 3}$.
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What element gives azurite its blue coloring?
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Which of the following minerals is NOT a constituent of basalt? W) Anorthite X) Augite Y) Olivine Z) Biotite
W: W) Anorthite
X: X) Augite
Y: Y) Olivine
Z: Z) Biotite
Answer: Z) Z) Biotite
A botanist wishes to prevent self-pollination in bluebells so he can conduct a controlled experiment involving artificial pollination of flowers by hand. How might he go about stopping self-pollination? W) Fasten mesh bags around flowers so pollinators cannot approach flowers X) Cut off flower sepals Y) Cut off flower petals Z) Cut off flower anthers
W: W) Fasten mesh bags around flowers so pollinators cannot approach flowers
X: X) Cut off flower sepals
Y: Y) Cut off flower petals
Z: Z) Cut off flower anthers
Answer: Z) Z) Cut off flower anthers
Which of the following would be the most direct product of meiosis in a typical plant? W) Gametophyte X) Spore Y) Egg Z) Sporophyte
W: W) Gametophyte
X: X) Spore
Y: Y) Egg
Z: Z) Sporophyte
Answer: X) X) Spore
Three resistors are connected to a battery in parallel. The resistors have resistances of 1 Ω, 100 Ω, and 1000 Ω. The equivalent resistance of the circuit is nearest to which of the following values? W) 1 Ω X) 100 Ω Y) 1000 Ω Z) 1101 Ω
W: W) 1 Ω
X: X) 100 Ω
Y: Y) 1000 Ω
Z: Z) 1101 Ω
Answer: W) W) 1 Ω
If it takes 12 seconds total for a ball to travel straight up from the ground and fall back to earth, neglecting air resistance and given $g = 10\,$m/s², what was the maximum height it reached in meters?
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Which of the following sources of energy produces radioactive waste? W) Hydrogen X) Geothermal Y) Coal Z) Oil
W: W) Hydrogen
X: X) Geothermal
Y: Y) Coal
Z: Z) Oil
Answer: Y) Y) Coal
A motor consumes 21 kW at 90% efficiency. Which of the following is closest to the difference in operating costs over 20 years for this motor versus a 95% efficient motor, assuming the motors run constantly and electricity costs \$0.10 per kWh? W) \$5,000 X) \$20,000 Y) \$27,000 Z) \$30,000
W: W) \$5,000
X: X) \$20,000
Y: Y) \$27,000
Z: Z) \$30,000
Answer: X) X) \$20,000
Which of the following elements has more p electrons than s electrons? W) Boron X) Magnesium Y) Germanium Z) Nitrogen
W: W) Boron
X: X) Magnesium
Y: Y) Germanium
Z: Z) Nitrogen
Answer: Y) Y) Germanium
Imperfections in solids have a distinct effect on the properties of the materials. Which of the following describes 2D defects? W) Pores and cracks X) Grain boundaries and surface defects Y) Vacancies and interstitials Z) Edge and screw dislocations
W: W) Pores and cracks
X: X) Grain boundaries and surface defects
Y: Y) Vacancies and interstitials
Z: Z) Edge and screw dislocations
Answer: X) X) Grain boundaries and surface defects
Find the slant height in units of a regular pyramid whose base is a 10×10 square and whose altitude is 12 units in length.
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What is the 19th derivative of $y = \sin x$?
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An example of a negative feedback mechanism is thermoregulation in animals. When an ectotherm begins to feel cold, which of the following typically happens? W) It sits in the Sun until it gets warm X) It uses metabolic energy to warm Y) It goes into torpor Z) Its body temperature cools to match the environment
W: W) It sits in the Sun until it gets warm
X: X) It uses metabolic energy to warm
Y: Y) It goes into torpor
Z: Z) Its body temperature cools to match the environment
Answer: W) W) It sits in the Sun until it gets warm
Chloroplasts in green algae have a double membrane, whereas chlorarachniophytes have chloroplasts with four membranes. Which of the following is a likely explanation for this observation? W) Chlorarachniophytes are an example of polyploidy X) Chlorarachniophyte chloroplasts are the result of ancient endosymbiosis of green algae with a eukaryote Y) Chlorarachniophyte chloroplasts are parasitic green algae living within the chlorarachniophyte Z) Chlorarachniophyte chloroplasts are the result of phagocytosis of cyanobacteria
W: W) Chlorarachniophytes are an example of polyploidy
X: X) Chlorarachniophyte chloroplasts are the result of ancient endosymbiosis of green algae with a eukaryote
Y: Y) Chlorarachniophyte chloroplasts are parasitic green algae living within the chlorarachniophyte
Z: Z) Chlorarachniophyte chloroplasts are the result of phagocytosis of cyanobacteria
Answer: X) X) Chlorarachniophyte chloroplasts are the result of ancient endosymbiosis of green algae with a eukaryote
What type of plate boundary shows primarily tensional stress?
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What is the name for a small-scale vent on a volcano from which gases escape into the atmosphere?
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A solid conducting sphere with radius 10 cm is charged with 20 μC. What is the electric field 5 cm from the center of the sphere?
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A boy standing at the top of a tower of height $h$ jumps to the ground. In simplest form, what is the exact expression for the speed with which he touches the ground, given $g$ as the magnitude of the acceleration due to gravity?
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Which of the following four substances would have the highest melting point? W) C₁₈H₃₈ X) H₂O Y) MgCl₂ Z) N₂O₅
W: W) C₁₈H₃₈
X: X) H₂O
Y: Y) MgCl₂
Z: Z) N₂O₅
Answer: Y) Y) MgCl₂
Which of the following statements about hydroboration-oxidation is false? W) It is a syn addition X) The borane acts as the electrophile Y) Overall, the reaction converts an alkene to an alcohol Z) The common oxidizing agent used is sodium borohydride
W: W) It is a syn addition
X: X) The borane acts as the electrophile
Y: Y) Overall, the reaction converts an alkene to an alcohol
Z: Z) The common oxidizing agent used is sodium borohydride
Answer: Z) Z) The common oxidizing agent used is sodium borohydride
Which of the following methods is NOT typically used to determine the proportion of guanine and cytosine base pairing in a sample of DNA? W) DNA sequencing X) Melting point Y) X-ray crystallography Z) Density gradient centrifugation
W: W) DNA sequencing
X: X) Melting point
Y: Y) X-ray crystallography
Z: Z) Density gradient centrifugation
Answer: Y) Y) X-ray crystallography
Which of the following populations would be most likely to exhibit logarithmic population growth? W) Elephants protected from hunting in a national park X) Sparrows that breed on a small island in northern Canada, with alternating mild and very harsh winters Y) Yeast growing under controlled laboratory conditions Z) Deer living in Yellowstone National Park with wolf predators present
W: W) Elephants protected from hunting in a national park
X: X) Sparrows that breed on a small island in northern Canada, with alternating mild and very harsh winters
Y: Y) Yeast growing under controlled laboratory conditions
Z: Z) Deer living in Yellowstone National Park with wolf predators present
Answer: Y) Y) Yeast growing under controlled laboratory conditions
Which of the following is equivalent to the expression $(x^2 - 2)^2$? W) $x^4 + 4$ X) $x^4 - 4x + 4$ Y) $x^4 - 4x^2 + 4$ Z) $x^4 - 4$
W: W) $x^4 + 4$
X: X) $x^4 - 4x + 4$
Y: Y) $x^4 - 4x^2 + 4$
Z: Z) $x^4 - 4$
Answer: Y) Y) $x^4 - 4x^2 + 4$
For a recursive sequence defined by $a_1 = 7$, $a_2 = 3$, and $a_n = a_{n-1} - a_{n-2}$ for $n \ge 3$, find $a_{1205}$. W) –4 X) –3 Y) 3 Z) 4
W: W) –4
X: X) –3
Y: Y) 3
Z: Z) 4
Answer: X) X) –3
Which of the following plates is currently subducting off the west coast of Central America? W) Juan de Fuca X) Nazca Y) Cocos Z) Gordo
W: W) Juan de Fuca
X: X) Nazca
Y: Y) Cocos
Z: Z) Gordo
Answer: Y) Y) Cocos
Of the following four factors, by number, identify those that will increase the rate of light attenuation in a natural water body: 1) Decreased particulate turbidity 2) Increased concentrations of plankton 3) Decreased chromophoric compounds 4) Increased dissolved organic carbon
Choices:
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A mysterious new disease has been discovered. The pathogen responsible can be easily viewed on a light microscope using a 4× objective with 10× ocular lenses. It desiccates easily, moves by changing the consistency of its cytoplasm, and does not contain peptidoglycan. In which group will this pathogen likely be classified? W) Amoeba X) Fungus Y) Bacterium Z) Virus
W: W) Amoeba
X: X) Fungus
Y: Y) Bacterium
Z: Z) Virus
Answer: W) W) Amoeba
A new species of fruit fly has brown or white wings. Brown-winged females are mated with white-winged males. In the F₁ generation, half of the females are brown and half of the males are brown. Which of the following is the best explanation? W) White wing color is a recessive X-linked trait X) Brown wing color is a recessive X-linked trait Y) White wing color is a recessive autosomal trait Z) White wing color is a lethal mutation
W: W) White wing color is a recessive X-linked trait
X: X) Brown wing color is a recessive X-linked trait
Y: Y) White wing color is a recessive autosomal trait
Z: Z) White wing color is a lethal mutation
Answer: W) W) White wing color is a recessive X-linked trait
A proton is moving north when it experiences a uniform magnetic field pointing vertically downward. In which cardinal direction should an electric field be applied to keep the proton moving due north?
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What is the kinetic energy in joules (to two significant figures) of a car with mass 2000 kg moving at 100 km/h?
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Despite the heat produced from hydrothermal vents on the ocean floor (up to 400 °C), the surrounding water does not boil. Why not? W) The surrounding water is too cold X) There is too much pressure at that depth Y) The salt concentration is too high Z) There is a low concentration of oxygen
W: W) The surrounding water is too cold
X: X) There is too much pressure at that depth
Y: Y) The salt concentration is too high
Z: Z) There is a low concentration of oxygen
Answer: X) X) There is too much pressure at that depth
Approximately how many horsepower are generated by a horse pulling with a force of 180 lb and turning a 24 ft diameter wheel 72 times in one hour? W) 1/2 X) 3/4 Y) 1 Z) 5/4
W: W) 1/2
X: X) 3/4
Y: Y) 1
Z: Z) 5/4
Answer: W) W) 1/2
Which of the following statements about phase diagrams is NOT true? W) The point at which all three phases coexist is called the critical point X) The line separating solid and vapor represents sublimation Y) The line separating liquid and vapor represents boiling Z) A negatively sloped line between the solid and liquid indicates that the solid will float in the liquid
W: W) The point at which all three phases coexist is called the critical point
X: X) The line separating solid and vapor represents sublimation
Y: Y) The line separating liquid and vapor represents boiling
Z: Z) A negatively sloped line between the solid and liquid indicates that the solid will float in the liquid
Answer: W) W) The point at which all three phases coexist is called the critical point
Which of the following is a characteristic of an adiabatic gas expansion? W) Internal energy increases X) Temperature of the working gas decreases Y) Kinetic energy increases with average molecular speed Z) Work done is inversely proportional to temperature difference between initial and final states
W: W) Internal energy increases
X: X) Temperature of the working gas decreases
Y: Y) Kinetic energy increases with average molecular speed
Z: Z) Work done is inversely proportional to temperature difference between initial and final states
Answer: X) X) Temperature of the working gas decreases
In the expansion of $(1 - 5x)^3$, what is the coefficient of $x^2$?
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Evaluate $\lim_{x\to1}\frac{-1 + \sqrt[3]{x}}{x - 1}$.
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Which of the following observations was NOT used as evidence for Alfred Wegener’s theory of continental drift? W) Seafloor bathymetry X) Glaciogenic sediments Y) Shoreline fit of continents Z) Fossil evidence
W: W) Seafloor bathymetry
X: X) Glaciogenic sediments
Y: Y) Shoreline fit of continents
Z: Z) Fossil evidence
Answer: W) W) Seafloor bathymetry
Which of the following minerals has the highest specific gravity? W) Galena X) Graphite Y) Goethite Z) Garnet
W: W) Galena
X: X) Graphite
Y: Y) Goethite
Z: Z) Garnet
Answer: W) W) Galena
Which of the following populations would be most likely to have a clumped distribution? W) Wolves that hunt in packs X) Thousands of seagulls nesting on a half-mile stretch of beach Y) A planted field of wheat Z) Dandelions growing from seeds dispersed by wind
W: W) Wolves that hunt in packs
X: X) Thousands of seagulls nesting on a half-mile stretch of beach
Y: Y) A planted field of wheat
Z: Z) Dandelions growing from seeds dispersed by wind
Answer: W) W) Wolves that hunt in packs
Bird wings and airplane wings have a highly similar shape. At the top of the wing, birds have a small feather called the alula, which extends during takeoff and landing. Which of the following is the purpose of the alula? W) Acts as a brake by increasing drag X) Makes the wing produce less lift Y) Reduces turbulence and maintains lift Z) Increases thrust
W: W) Acts as a brake by increasing drag
X: X) Makes the wing produce less lift
Y: Y) Reduces turbulence and maintains lift
Z: Z) Increases thrust
Answer: Y) Y) Reduces turbulence and maintains lift
In an electromagnetic wave, the $\mathbf{E}$ field vector points in the positive $x$ direction and the $\mathbf{B}$ field vector points in the negative $y$ direction. What is the direction of propagation of the wave?
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Let $g$ represent the acceleration due to gravity at the surface of the Earth. A planet with one third of the mass of the Earth and one half of the radius of the Earth will have an acceleration due to gravity near its surface that is which of the following? W) One third $g$ X) Two thirds $g$ Y) $g$ Z) Four thirds $g$
W: W) One third $g$
X: X) Two thirds $g$
Y: Y) $g$
Z: Z) Four thirds $g$
Answer: Z) Z) Four thirds $g$
Photosynthesis accounts for the fixation of about 200 billion tons of carbon. Approximately which of the following percentages of this carbon is fixed by marine plankton alone? W) 8% X) 24% Y) 40% Z) 65%
W: W) 8%
X: X) 24%
Y: Y) 40%
Z: Z) 65%
Answer: Y) Y) 40%
Rank the four following forms of coal in order of energy per pound from least to greatest: 1) bituminous; 2) anthracite; 3) lignite; 4) sub-bituminous.
Choices:
Correct Order:
Consider the reaction 2 C₂H₆(g) + 7 O₂(g) → 4 CO₂(g) + 6 H₂O(l) in which ΔH = –3120 kJ. If 3.00 g of ethane are burned, how many kilojoules of heat are produced? W) 1560 X) 624 Y) 312 Z) 156
W: W) 1560
X: X) 624
Y: Y) 312
Z: Z) 156
Answer: Z) Z) 156
An element’s most stable ion forms an ionic compound with iodine having the formula XI₂. If the ion of element X has a mass of 89 amu and has 36 electrons, which of the following correctly matches the identity of the element and how many neutrons it has? W) Strontium and 51 X) Krypton and 55 Y) Selenium and 55 Z) Krypton and 53
W: W) Strontium and 51
X: X) Krypton and 55
Y: Y) Selenium and 55
Z: Z) Krypton and 53
Answer: W) W) Strontium and 51
The population growth rate of a sparrow community at carrying capacity on a small island depends on the number of individuals present. What effect would an increase in population size have on the birth rate of sparrows?
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On a mountainside, Species A lives at 4500–7000 ft. You believe Species B, which lives at 6500–9000 ft, is not an effective competitor against Species A. You decide to implement one of the following choices and then observe Species B for at least one year. Which test would be most effective in answering your question? W) Release 100 pairs of Species B at elevations between 4500 and 5500 ft X) Remove all members of Species A living between 5500 and 7000 ft Y) Release 100 pairs of Species A at elevations between 7000 and 9000 ft Z) Capture one bird of each species and test its physiological adaptations
W: W) Release 100 pairs of Species B at elevations between 4500 and 5500 ft
X: X) Remove all members of Species A living between 5500 and 7000 ft
Y: Y) Release 100 pairs of Species A at elevations between 7000 and 9000 ft
Z: Z) Capture one bird of each species and test its physiological adaptations
Answer: X) X) Remove all members of Species A living between 5500 and 7000 ft