The roller coaster diagram shows a set of cars moving downward from position 1 to position 2. As the cars travel from position 1 toward position 2, their...
- A. gravitational potential energy; total energy
- B. kinetic energy; gravitational potential energy
- C. total energy; kinetic energy
- D. gravitational potential energy; kinetic energy
Correct Answer & Rationale
Correct Answer: A
As the roller coaster cars move from position 1 to position 2, they descend, resulting in a decrease in gravitational potential energy due to their lower height. However, their total energy—comprising both kinetic and potential energy—remains constant, assuming negligible friction. Option B incorrectly suggests that kinetic energy increases while gravitational potential energy decreases, but it does not address total energy. Option C misrepresents the relationship by stating total energy changes, which it does not. Option D also fails, as it inaccurately implies that gravitational potential energy is the only energy type being discussed.
As the roller coaster cars move from position 1 to position 2, they descend, resulting in a decrease in gravitational potential energy due to their lower height. However, their total energy—comprising both kinetic and potential energy—remains constant, assuming negligible friction. Option B incorrectly suggests that kinetic energy increases while gravitational potential energy decreases, but it does not address total energy. Option C misrepresents the relationship by stating total energy changes, which it does not. Option D also fails, as it inaccurately implies that gravitational potential energy is the only energy type being discussed.
Other Related Questions
Which hypothesis is suitable for this investigation?
- A. Body temperature, breathing rate, and heart rate depend on the health of the subject.
- B. Many of the body's systems respond to exercise.
- C. Body temperature, breathing rate, and heart rate increase with exercise.
- D. Subjects at rest have better health than subjects that exercise.
Correct Answer & Rationale
Correct Answer: C
Option C effectively addresses the investigation by predicting a specific relationship: that body temperature, breathing rate, and heart rate will increase with exercise. This hypothesis is testable and directly relates to physiological responses during physical activity. Option A is too broad, as it suggests a general relationship between health and various physiological metrics without focusing on exercise. Option B, while relevant, lacks specificity regarding the measurable changes in body temperature, breathing rate, and heart rate. Option D presents a misleading comparison, as it contradicts established knowledge about the benefits of exercise for health.
Option C effectively addresses the investigation by predicting a specific relationship: that body temperature, breathing rate, and heart rate will increase with exercise. This hypothesis is testable and directly relates to physiological responses during physical activity. Option A is too broad, as it suggests a general relationship between health and various physiological metrics without focusing on exercise. Option B, while relevant, lacks specificity regarding the measurable changes in body temperature, breathing rate, and heart rate. Option D presents a misleading comparison, as it contradicts established knowledge about the benefits of exercise for health.
Scientists can indirectly observe temperatures and insolation (the Intensity or direct solar radiation) in the distant past by measuring oxygen isotope ratios in ice cores collected from polar ice. The graph presents data for the period from what ta200.000 years ago. What time period in the graph shows the greatest correlation between Milankovitch cycles and climate?
- A. 140,000-160,000 years ago
- B. 120,000-140,000 years ago
- C. 100,000-120,000 years ago
- D. 160,000-180,000 years ago
Correct Answer & Rationale
Correct Answer: C
The time period from 100,000 to 120,000 years ago exhibits the greatest correlation between Milankovitch cycles and climate, as evidenced by significant fluctuations in temperature and insolation reflected in the oxygen isotope ratios. This interval aligns closely with the timing of glacial and interglacial periods influenced by Earth's orbital changes. Options A and B show notable climate changes, but they do not align as strongly with Milankovitch cycles, indicating less correlation. Option D, while part of the broader glacial cycle, reveals less pronounced temperature shifts, making it less relevant to the question of correlation.
The time period from 100,000 to 120,000 years ago exhibits the greatest correlation between Milankovitch cycles and climate, as evidenced by significant fluctuations in temperature and insolation reflected in the oxygen isotope ratios. This interval aligns closely with the timing of glacial and interglacial periods influenced by Earth's orbital changes. Options A and B show notable climate changes, but they do not align as strongly with Milankovitch cycles, indicating less correlation. Option D, while part of the broader glacial cycle, reveals less pronounced temperature shifts, making it less relevant to the question of correlation.
Which statement explains the central idea of the passage?
- A. People should consume as much magnesium as possible to ensure good cardiovascular health.
- B. People may experience health benefits from drinking hard water because it contains magnesium.
- C. People who live in rural environments are healthier than people who live in urban environments.
- D. People should stop the practice of softening water because it removes minerals that are necessary for good health.
Correct Answer & Rationale
Correct Answer: B
Option B accurately reflects the central idea by highlighting the potential health benefits of magnesium found in hard water. This aligns with the passage's focus on the relationship between magnesium intake and cardiovascular health. Option A is misleading as it suggests an excessive intake of magnesium is necessary, while the passage likely emphasizes balance rather than maximum consumption. Option C incorrectly generalizes health comparisons between rural and urban populations without specific evidence from the passage. Option D misrepresents the passage's message by implying a complete cessation of water softening, rather than discussing the importance of maintaining essential minerals like magnesium.
Option B accurately reflects the central idea by highlighting the potential health benefits of magnesium found in hard water. This aligns with the passage's focus on the relationship between magnesium intake and cardiovascular health. Option A is misleading as it suggests an excessive intake of magnesium is necessary, while the passage likely emphasizes balance rather than maximum consumption. Option C incorrectly generalizes health comparisons between rural and urban populations without specific evidence from the passage. Option D misrepresents the passage's message by implying a complete cessation of water softening, rather than discussing the importance of maintaining essential minerals like magnesium.
The chemical composition and energy density of four fuels are shown in the table. Ethane, which has a chemical composition of C2H6, is also a fuel. What is the predicted energy density of ethane?
- A. 45 MJ/kg
- B. 42 MJ/kg
- C. 52 MJ/kg
- D. 48 MJ/kg
Correct Answer & Rationale
Correct Answer: C
To determine the predicted energy density of ethane (C2H6), one can analyze its molecular structure and compare it to the energy densities of similar hydrocarbons listed in the table. Ethane, being an alkane, typically has a higher energy density due to its saturated carbon-hydrogen bonds. Option A (45 MJ/kg) is lower than expected for alkanes of similar size. Option B (42 MJ/kg) underestimates the energy density, as it does not align with the general trend for hydrocarbons. Option D (48 MJ/kg) is closer but still below the typical range for ethane. Thus, option C (52 MJ/kg) aligns with the expected energy density for ethane, reflecting its molecular composition and energy potential.
To determine the predicted energy density of ethane (C2H6), one can analyze its molecular structure and compare it to the energy densities of similar hydrocarbons listed in the table. Ethane, being an alkane, typically has a higher energy density due to its saturated carbon-hydrogen bonds. Option A (45 MJ/kg) is lower than expected for alkanes of similar size. Option B (42 MJ/kg) underestimates the energy density, as it does not align with the general trend for hydrocarbons. Option D (48 MJ/kg) is closer but still below the typical range for ethane. Thus, option C (52 MJ/kg) aligns with the expected energy density for ethane, reflecting its molecular composition and energy potential.