Please answer this: The frequency of sound waves is measured in hertz (Hz), or the number of waves that pass a fixed point in a second. Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound . Sounds with frequencies above 20,000 hertz are called ultrasound . Some other animals can hear sounds in the ultrasound range. For example, dogs can hear sounds with frequencies as high as 50,000 Hz. You may have seen special whistles that dogs but not people can hear. The whistles produce a sound with a frequency too high for the human ear to detect. Other animals can hear even higher-frequency sounds. Bats, for example, can hear sounds with frequencies higher than 100,000 Hz. David wants to categorize animals according to the sound waves they can hear. Eventually, he was able to categorize them in three different groups, group A, group B, and group C. He placed the animals that can only hear ifrasound in group A. Then he placed the animals that are only able to hear the same frequency of sound waves as humans do in group B. The last group of animals were able to hear only ultrasound. He placed them in group C. Would group B able to hear higher or lower frequency than group A?
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Answer: higher

Problem: A major use for petroleum products is fuel for cars, trucks, airplanes, trains, and other vehicles. The chemical used are usually a mixture of compounds containing several carbon atoms in a chain. When the material is ignited, a massive amount of gas is created almost instantaneously. This increase in volume will move the pistons in an internal combustion engine to provide power. A jet plane works on a similar principle. Air comes into the front of the engine and mixes with the jet fuel. This mixture is ignited and the gases formed create a lot of pressure to push the plane forward. The idea can be seen even more clearly in the case of a rocket launch. The ignition of the fuel (either solid-state or liquid) creates gases produced under great pressure that pushes the rocket up. Two engineering students learned about petroleum products, While Dan learned more about plastics, Jim learned about fuels. Which student learned less about fuels for trains?

A: Dan

Problem: Given the question: Soil is well developed in the forest as suggested by the thick humus layers, rich diversity of large trees and animals that live there. In forests, precipitation exceeds evapotranspiration which results in an excess of water that percolates downward through the soil layers. Slow rates of decomposition leads to large amounts of fulvic acid, greatly enhancing chemical weathering. The downward percolation, in conjunction with chemical weathering leaches magnesium (Mg), iron (Fe), and aluminum (Al) from the soil and transports them downward, a process known as podzolization. This process leads to marked contrasts in the appearance and chemistry of the soil layers. Two brothers owned two adjacent parcels of land. Tom's land was forested, while Bill's was covered with grasslands. Which parcel of land didn't have an excess of water that percolates downward through the soil layers?
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The answer is:
Bill's

input question: Any unused energy in food, whether it comes from carbohydrates, proteins, or lipids, is stored in the body as fat. An extra 3,500 Calories of energy results in the storage of almost half a kilogram (1 pound) of stored body fat. People who consistently consume more food energy then they need may become obese. Obesity occurs when the body mass index is 30.0 kg/m 2 or greater. Body mass index (BMI) is an estimate of the fat content of the body. It is calculated by dividing a person's weight (in kilograms) by the square of the person's height (in meters). Obesity increases the risk of health problems such as type 2 diabetes and hypertension. Jerry and George are two roommates who have lived together since college. They have always gotten along well, have similar hobbies and even are the same height. They both enjoy watching sports and playing videogames, but Jerry also rides his bike several miles each week. George can't stand exercising. Instead, he prefers to lay around relaxing and driving his car if he needs to go somewhere. Who has a higher risk of hypertension????
output answer: George

Higher pressures increase the solubility of gases. You are probably familiar with this concept as it relates to carbonated beverages. Before opening the container, the inside is pressurized, so a large amount of CO 2 is dissolved in the liquid. After opening, the pressure decreases (to the ambient pressure), so the solubility of CO 2 drops, causing it to bubble out of solution. Because they are not compressible like gases, solid and liquid solutes do not have noticeable changes in solubility at different external pressures. Robin is an exterminator who is making new mixtures of chemicals to use for when he gets called to kill rats in his neighborhood. To make the mixtures, he has to dissolve nitrogen gas in containers of water. In one container, container A, he dissolves the nitrogen gas under high pressure. In the other container, container B, he dissolves the nitrogen gas under low pressure. Which container will have lower solubility of the nitrogen gas?
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Answer: container B

Q: Saturated hydrocarbons are given the general name of alkanes . The name of specific alkanes always ends in ane . The first part of the name indicates how many carbon atoms each molecule of the alkane has. The smallest alkane is methane. It has just one carbon atom. The next largest is ethane with two carbon atoms. The chemical formulas and properties of methane, ethane, and other small alkanes are listed in the Table below . The boiling and melting points of alkanes are determined mainly by the number of carbon atoms they have. Alkanes with more carbon atoms generally boil and melt at higher temperatures. Two sisters Mary and Beth were into sciences. Beth studied physics, while Mary studied chemistry and especially alkanes. They were very devoted to studying. Which sister studied more about methane?
A:
Mary