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 best predicts what will happen when white light passes through a green object?
- A. The object will mostly reflect the green part of the light.
- B. The object will mostly absorb the green part of the light.
- C. The object will appear black.
- D. The object will appear white.
Correct Answer & Rationale
Correct Answer: A
When white light passes through a green object, the object primarily reflects green wavelengths while absorbing others. This reflection causes the object to appear green to our eyes. Option B is incorrect because if the object absorbed the green part of the light, it would not appear green. Option C is not valid, as a black appearance would result from the object absorbing all wavelengths of light, not reflecting any. Option D is also wrong; an object appears white when it reflects all wavelengths of light equally, which does not apply to a green object.
When white light passes through a green object, the object primarily reflects green wavelengths while absorbing others. This reflection causes the object to appear green to our eyes. Option B is incorrect because if the object absorbed the green part of the light, it would not appear green. Option C is not valid, as a black appearance would result from the object absorbing all wavelengths of light, not reflecting any. Option D is also wrong; an object appears white when it reflects all wavelengths of light equally, which does not apply to a green object.
Earth's diameter is approximately 12,700 kilometers. Which of the following layers is located approximately 6,000 kilometers beneath Earth's surface and is composed primarily of iron and nickel?
- A. The core
- B. The crust
- C. The lithosphere
- D. The mantle
Correct Answer & Rationale
Correct Answer: A
The core, located about 6,000 kilometers beneath Earth's surface, is primarily composed of iron and nickel, making it the densest layer of the planet. The crust, option B, is the outermost layer and is much shallower, averaging only about 30 kilometers thick. Option C, the lithosphere, includes the crust and the uppermost part of the mantle, but it does not reach anywhere near 6,000 kilometers deep. The mantle, option D, lies between the crust and the core, extending to about 2,900 kilometers down, but it is primarily composed of silicate minerals, not iron and nickel.
The core, located about 6,000 kilometers beneath Earth's surface, is primarily composed of iron and nickel, making it the densest layer of the planet. The crust, option B, is the outermost layer and is much shallower, averaging only about 30 kilometers thick. Option C, the lithosphere, includes the crust and the uppermost part of the mantle, but it does not reach anywhere near 6,000 kilometers deep. The mantle, option D, lies between the crust and the core, extending to about 2,900 kilometers down, but it is primarily composed of silicate minerals, not iron and nickel.
A metal spoon that heats up while sitting in a bowl of hot soup is an example of heat transfer by:
- A. conduction
- B. convection
- C. radiation
- D. diffusion
Correct Answer & Rationale
Correct Answer: A
Heat transfer occurs through different mechanisms, and in this scenario, the metal spoon absorbs heat from the hot soup primarily through conduction. Conduction involves direct contact, where heat moves from the hot soup molecules to the cooler spoon molecules. Convection, option B, refers to heat transfer through fluid movement, which does not apply here since the spoon is not moving the soup. Radiation, option C, involves heat transfer through electromagnetic waves, which is not relevant in this case as there is no significant radiation involved. Lastly, diffusion, option D, pertains to the movement of particles from areas of high concentration to low concentration and is unrelated to heat transfer in this context.
Heat transfer occurs through different mechanisms, and in this scenario, the metal spoon absorbs heat from the hot soup primarily through conduction. Conduction involves direct contact, where heat moves from the hot soup molecules to the cooler spoon molecules. Convection, option B, refers to heat transfer through fluid movement, which does not apply here since the spoon is not moving the soup. Radiation, option C, involves heat transfer through electromagnetic waves, which is not relevant in this case as there is no significant radiation involved. Lastly, diffusion, option D, pertains to the movement of particles from areas of high concentration to low concentration and is unrelated to heat transfer in this context.
Which of the following best describes what happens when two magnets repel each other?
- A. The objects are pulled toward one another.
- B. The objects are pushed away from one another.
- C. An electric spark jumps from one object to another.
- D. Nothing happens until the objects are touched.
Correct Answer & Rationale
Correct Answer: B
When two magnets repel each other, they exert forces that push away from one another due to their like poles (north-north or south-south). This repulsion is a fundamental property of magnetism. Option A is incorrect because it describes attraction, which occurs when opposite poles (north-south) interact. Option C is misleading; electric sparks are not a typical result of magnet repulsion. Option D is also wrong, as repulsion occurs before any physical contact, demonstrating the active interaction between the magnets. Thus, the best description of this phenomenon is that the objects are pushed away from one another.
When two magnets repel each other, they exert forces that push away from one another due to their like poles (north-north or south-south). This repulsion is a fundamental property of magnetism. Option A is incorrect because it describes attraction, which occurs when opposite poles (north-south) interact. Option C is misleading; electric sparks are not a typical result of magnet repulsion. Option D is also wrong, as repulsion occurs before any physical contact, demonstrating the active interaction between the magnets. Thus, the best description of this phenomenon is that the objects are pushed away from one another.