Problem: Keith landed a job with the EPA. As part of his training he needed to learn how the Geiger counter works. To learn more about the counter he tested it in three different locations, location A, location B, and location C. Location A had very high radiation; location B had low radiation; and location C didn't have any radiation. Keith learned how the counter works in locations with varying degrees of radiation. Given the paragraph above, please answer correctly the following question: Would location A have faster or slower clicks than location B? Hint: You generally can't see, smell, taste, hear, or feel radiation. Fortunately, there are devices such as Geiger counters that can detect radiation. A Geiger counter, like the one pictured in the Figure below , contains atoms of a gas that is ionized if it encounters radiation. When this happens, the gas atoms change to ions that can carry an electric current. The current causes the Geiger counter to click. The faster the clicks occur, the higher the level of radiation. You can see a video about the Geiger counter and how it was invented at the URL below.

A: faster

Problem: Tom and Jerry are two friends who have always had competitions with one another throughout their whole lives. Yesterday, they just finished their most unique competition so far. Each man was given a room to sit in that had several highly radioactive objects in it. The challenge was to see who would stay in the chamber longer. Tom didn't stay in his room for very long, but Jerry felt determined to win and stayed in his chamber almost the entire day. Given the paragraph above, please answer correctly the following question: Who is less likely to need a liver transplant? Hint: Ionizing radiation has many practical uses in medicine, research and construction, but presents a health hazard if used improperly. Exposure to radiation causes damage to living tissue; high doses result in Acute radiation syndrome (ARS), with skin burns, hair loss, internal organ failure and death, while any dose may result in an increased chance of cancer and genetic damage; a particular form of cancer, thyroid cancer, often occurs when nuclear weapons and reactors are the radiation source because of the biological proclivities of the radioactive iodine fission product, iodine-131. However, calculating the exact risk and chance of cancer forming in cells caused by ionizing radiation is still not well understood and currently estimates are loosely determined by population based data from the atomic bombings of Hiroshima and Nagasaki and from follow-up of reactor accidents, such as the Chernobyl disaster. The International Commission on Radiological Protection states that "The Commission is aware of uncertainties and lack of precision of the models and parameter values", "Collective effective dose is not intended as a tool for epidemiological risk assessment, and it is inappropriate to use it in risk projections" and "in particular, the calculation of the number of cancer deaths based on collective effective doses from trivial individual doses should be avoided."

A: Tom

Problem: John was sitting at point C near a railway track. Suddenly, he heard a train coming towards him from point A with constant sound of its horn. Eventually, it reached very close to him at point B. Then the train sped by him at point C where he was sitting, reaching point D after some time. Finally, it reached even farther from him at point E. Given the paragraph above, please answer correctly the following question: At which point the horn would sound higher in pitch, point A or point B? Hint: Look at the police car in Figure below . The sound waves from its siren travel outward in all directions. Because the car is racing forward (toward the right), the sound waves get bunched up in front of the car and spread out behind it. As the car approaches the person on the right (position B), the sound waves get closer and closer together. In other words, they have a higher frequency. This makes the siren sound higher in pitch. After the car speeds by the person on the left (position A), the sound waves get more and more spread out, so they have a lower frequency. This makes the siren sound lower in pitch. A change in the frequency of sound waves, relative to a stationary listener, when the source of the sound waves is moving is called the Doppler effect . You've probably experienced the Doppler effect yourself. The next time a vehicle with a siren races by, listen for the change in pitch. For an online animation of the Doppler effect, go to the URL below.

A: point B

Problem: Rob is an environmental scientist. He was doing a study on agroforestry. To test the sustainability of agroforestry he conducted two pilot projects, pilot A and pilot B. In pilot A, he used a land for agrofroestry. In pilot B, he used a land for usual row-cropping. He needed to find the pros and cons of both systems. Given the paragraph above, please answer correctly the following question: Which project would have lower nutrient uptake, pilot A or pilot B? Hint: Depleted soils can be protected from soil erosion by groundcover plants such as naturally growing grasses in agroforestry systems. These help to stabilise the soil as they increase cover compared to short-cycle cropping systems. Soil cover is a crucial factor in preventing erosion. Cleaner water through reduced nutrient and soil surface runoff can be a further advantage of agroforestry. The runoff can be reduced by decreasing its velocity and increasing infiltration into the soil. Compared to row-cropped fields nutrient uptake can be higher and reduce nutrient loss into streams.Further advantages concerning plant growth:

A:
pilot A