Students investigated the effect of wingspan length on the flight of several toy gliders that had different wingspans. For each trial, they measure and the amount of time in the air using a stopwatch.
Which of the following was the dependent variable in this investigation?
- A. The wingspan
- B. The flight distance
- C. The stopwatch
- D. The tape measure
Correct Answer & Rationale
Correct Answer: B
In this investigation, the dependent variable is the outcome that is measured in response to changes in the independent variable. Flight distance (B) reflects how far something travels, which depends on the conditions set by the experiment. Wingspan (A) is an independent variable if it is being manipulated to see its effect on flight distance. The stopwatch (C) is a tool used to measure time and does not represent a variable in the experiment. Similarly, the tape measure (D) is an instrument for measuring distance, not a variable being tested. Thus, flight distance is the key outcome that reflects the effects of the experiment.
In this investigation, the dependent variable is the outcome that is measured in response to changes in the independent variable. Flight distance (B) reflects how far something travels, which depends on the conditions set by the experiment. Wingspan (A) is an independent variable if it is being manipulated to see its effect on flight distance. The stopwatch (C) is a tool used to measure time and does not represent a variable in the experiment. Similarly, the tape measure (D) is an instrument for measuring distance, not a variable being tested. Thus, flight distance is the key outcome that reflects the effects of the experiment.
Other Related Questions
Which of the following is always true of a chemical change?
- A. Color, shape, or texture is altered.
- B. Mass is increased.
- C. A new substance is formed.
- D. Gas or vapor is generated.
Correct Answer & Rationale
Correct Answer: C
A chemical change always results in the formation of a new substance, which is a fundamental characteristic distinguishing it from physical changes. Option A is incorrect because while color, shape, or texture may change, these alterations do not confirm a chemical change unless a new substance is produced. Option B is misleading; mass is conserved in chemical reactions, so it does not necessarily increase. Option D, while often true (as gases can be produced), is not universally applicable; some reactions do not produce gas. Hence, the formation of a new substance is the definitive indicator of a chemical change.
A chemical change always results in the formation of a new substance, which is a fundamental characteristic distinguishing it from physical changes. Option A is incorrect because while color, shape, or texture may change, these alterations do not confirm a chemical change unless a new substance is produced. Option B is misleading; mass is conserved in chemical reactions, so it does not necessarily increase. Option D, while often true (as gases can be produced), is not universally applicable; some reactions do not produce gas. Hence, the formation of a new substance is the definitive indicator of a chemical change.
Which of the following plant structures are specialized for the absorption of water and nutrients from the environment?
- A. Roots
- B. Leaves
- C. Flowers
- D. Stems
Correct Answer & Rationale
Correct Answer: A
Roots are specialized structures designed for the absorption of water and nutrients from the soil, featuring a large surface area and root hairs that enhance their efficiency. Leaves primarily function in photosynthesis and gas exchange, not nutrient absorption. Flowers are reproductive structures that facilitate pollination and seed production, playing no direct role in nutrient uptake. Stems support the plant and transport water and nutrients between roots and leaves, but they do not absorb them. Thus, roots are uniquely equipped for this essential task.
Roots are specialized structures designed for the absorption of water and nutrients from the soil, featuring a large surface area and root hairs that enhance their efficiency. Leaves primarily function in photosynthesis and gas exchange, not nutrient absorption. Flowers are reproductive structures that facilitate pollination and seed production, playing no direct role in nutrient uptake. Stems support the plant and transport water and nutrients between roots and leaves, but they do not absorb them. Thus, roots are uniquely equipped for this essential task.
Which of the following is true about the nucleus of an atom?
- A. The nucleus has a negative charge.
- B. The nucleus is neutral with no charge.
- C. The electrons and protons are located in the nucleus.
- D. The neutrons and protons are located in the nucleus.
Correct Answer & Rationale
Correct Answer: D
The nucleus of an atom is composed of protons and neutrons, making option D accurate. Protons carry a positive charge, while neutrons are neutral, contributing to the overall positive charge of the nucleus. Option A is incorrect because the nucleus does not have a negative charge; it is positively charged due to protons. Option B is also wrong, as the nucleus is not neutral; it has a positive charge from the protons. Lastly, option C is misleading because electrons are located outside the nucleus in electron shells, not within it.
The nucleus of an atom is composed of protons and neutrons, making option D accurate. Protons carry a positive charge, while neutrons are neutral, contributing to the overall positive charge of the nucleus. Option A is incorrect because the nucleus does not have a negative charge; it is positively charged due to protons. Option B is also wrong, as the nucleus is not neutral; it has a positive charge from the protons. Lastly, option C is misleading because electrons are located outside the nucleus in electron shells, not within it.
Which of the following is a nonrenewable fossil fuel?
- A. Coal
- B. Uranium
- C. Geothermal energy
- D. Ethanol
Correct Answer & Rationale
Correct Answer: A
Coal is a nonrenewable fossil fuel formed from ancient organic matter subjected to heat and pressure over millions of years. It is finite and cannot be replenished on a human timescale. Uranium (B) is a nonrenewable resource used in nuclear energy production but is not classified as a fossil fuel. Geothermal energy (C) harnesses heat from the Earth and is considered renewable. Ethanol (D) is a biofuel derived from plant materials, making it renewable as it can be produced continuously. Thus, coal stands out as the only nonrenewable fossil fuel in this list.
Coal is a nonrenewable fossil fuel formed from ancient organic matter subjected to heat and pressure over millions of years. It is finite and cannot be replenished on a human timescale. Uranium (B) is a nonrenewable resource used in nuclear energy production but is not classified as a fossil fuel. Geothermal energy (C) harnesses heat from the Earth and is considered renewable. Ethanol (D) is a biofuel derived from plant materials, making it renewable as it can be produced continuously. Thus, coal stands out as the only nonrenewable fossil fuel in this list.