Answer the following question given this paragraph: Did you ever see a meteor shower, like the one in Figure below ? Meteors burn as they fall through the mesosphere. The space rocks experience friction with the gas molecules. The friction makes the meteors get very hot. Many meteors burn up completely in the mesosphere. Q: What happens to meteors as they fall through the mesosphere? Choices: - they grow - they bounce - they stop suddenly - they burn A:
they burn
Answer the following question given this paragraph: The Dutch scientist Christiaan Huygens (16291695) developed a useful technique for determining in detail how and where waves propagate. Starting from some known position, Huygens's principle states that: Every point on a wavefront is a source of wavelets that spread out in the forward direction at the same speed as the wave itself. The new wavefront is a line tangent to all of the wavelets. Figure 27.5 shows how Huygens's principle is applied. A wavefront is the long edge that moves, for example, the crest or the trough. Each point on the wavefront emits a semicircular wave that moves at the propagation speed v . These are drawn at a time t later, so that they have moved a distance s = vt . The new wavefront is a line tangent to the wavelets and is where we would expect the wave to be a time t later. Huygens's principle works for all types of waves, including water waves, sound waves, and light waves. We will find it useful not only in describing how light waves propagate, but also in explaining the laws of reflection and refraction. In addition, we will see that Huygens's principle tells us how and where light rays interfere. Q: Dutch scientist christiaan huygens' principle of what states that every point on a wavefront is a source of wavelets that spread out in the forward direction at the speed of the wave itself? Choices: - electromagnetic dynamics - energy propagation - wave dynamics - wave propagation A:
wave propagation
Q: Answer the following question given this paragraph: Solution The charges, as well as the atoms, must balance in reactions. The silver atom is being oxidized from the 0 oxidation state to the 1+ state. Whenever something loses electrons, something must also gain electrons (be reduced) to balance the equation. Oxygen is a good oxidizing agent for these reactions because it can gain electrons to go from the 0 oxidation state to the 2 state. Q: When something loses electrons, it must also? Choices: - reduce protons - slow down - gain protons - gain electrons A:
A: gain electrons
Question: Answer the following question given this paragraph: Q: What type of animal eats both plants and animals? Choices: - insectivores - carnivores - herbivores - omnivores A:
Answer: omnivores
*Question*
Answer the following question given this paragraph: Most circuits have devices such as light bulbs that convert electric energy to other forms of energy. In the case of a light bulb, electricity is converted to light and thermal energy. Q: In the case of a light bulb, electricity is converted to light and what kind of energy? Choices: - nuclear - abstract - chemical - thermal A:
**Answer**
thermal
Answer the following question given this paragraph: A cell that does not have a rigid cell wall (such as a red blood cell), will swell and lyse (burst) when placed in a hypotonic solution. Cells with a cell wall will swell when placed in a hypotonic solution, but once the cell is turgid (firm), the tough cell wall prevents any more water from entering the cell. When placed in a hypertonic solution, a cell without a cell wall will lose water to the environment, shrivel, and probably die. In a hypertonic solution, a cell with a cell wall will lose water too. The plasma membrane pulls away from the cell wall as it shrivels, a process called plasmolysis. Animal cells tend to do best in an isotonic environment, plant cells tend to do best in a hypotonic environment. This is demonstrated in Figure below . Q: The plasma membrane pulls away from the cell wall as it shrivels. what is this process called? Choices: - sporozoans - fluctuations - osmosis - plasmolysis A:
plasmolysis