Problem: The Laffer curve depicts the amount of government revenue as a function of the rate of taxation. It shows that for a tax rate above a certain critical rate, government revenue starts decreasing as the tax rate rises, as a consequence of a decline in labour supply. This theory supports that, if the tax rate is above that critical point, a decrease in the tax rate should imply a rise in labour supply that in turn would lead to an increase in government revenue.  The country of Hinland reduced taxation hoping it would mean more money for government spending. On the other hand, Silvania, a southern country increased taxation hoping they would increase collection amounts. The problem was that Silvanian people increased taxation above the critical rate.  Which country increased their taxes?

A: Silvania


Problem: Vapor pressure is a measure of the pressure exerted by a gas above a liquid in a sealed container. While viscosity and surface tension increase as the strength of intermolecular forces increase, vapor pressure decreases . This is because the stronger the intermolecular forces are, the harder it is for liquid molecules to escape into the gas phase. Vapor pressure a measure of how much of a substance is in the gas phase when that substance is at equilibrium; that is, the number of molecules in the gas and liquid phases are not changing. The more molecules that are able to escape into the gas phase, the higher the vapor pressure. Vapor pressure is also proportional to temperature. As temperature increases, vapor pressure also increases.  As a part of his engineering job Keith is measuring the vapor pressure of two locomotives, engine A and engine B.  Engine A has a high vapor pressure, but engine B has a low vapor pressure. He noticed that to increase the speed of the engines he needed to increase the vapor pressure.  In which engine more liquid molecules would turn into gas phase, engine A or engine B?

A: engine A


Problem: Air pollution is harmful to human beings and other living things. About 22 million people die from air pollution each year. Breathing polluted air increases the risk of developing lung diseases such as asthma and lung cancer. Breathing bad air also increases the chances of dying from other diseases. Children are most likely to be affected by air pollution. That’s because their lungs are still developing and growing. Children also take in more air for their size than adults do. Some air pollutants damage the environment as well as the health of living things. The type of damage depends on the pollutant. Air pollution can also harm the environment.  Michael and Thomas are brothers whose careers have taken them to different cities. Michael lives in Beijing, where the levels of air pollution are fairly high due to the extensive manufacturing industry. Thomas, on the other hand, lives in Seattle, which has low levels of air pollution thanks to government initiatives and culture attitudes in the region.  Who has a higher risk of dying from diseases other than lung diseases?

A: Michael


Problem: Clouds on Earth are made of water vapor. Venus's clouds are a lot less pleasant. They are made of carbon dioxide, sulfur dioxide and large amounts of corrosive sulfuric acid! The atmosphere of Venus is so thick that the pressure on the surface of Venus is very high. In fact, it is 90 times greater than the pressure at Earth’s surface! The thick atmosphere causes a strong greenhouse effect. As a result, Venus is the hottest planet. Even though it is farther from the Sun, Venus is much hotter even than Mercury. Temperatures at the surface reach 465°C (860°F). That’s hot enough to melt lead!  Two teams of students studied Earth's atmosphere in class. They also started studying Venus' atmosphere. They were fascinated by the subject and learned a lot. Team A studied Earth, team B studied planet Venus.  Which team didn't learn about sulfur dioxide clouds?

A: