Ques: Answer the following question given this paragraph: Discussion for (a) This value is the net work done on the package. The person actually does more work than this, because friction opposes the motion. Friction does negative work and removes some of the energy the person expends and converts it to thermal energy. The net work equals the sum of the work done by each individual force. Strategy and Concept for (b) The forces acting on the package are gravity, the normal force, the force of friction, and the applied force. The normal force and force of gravity are each perpendicular to the displacement, and therefore do no work. Solution for (b) The applied force does work. Q: Friction does negative work and removes some of the energy the person expends and converts it to which kind of energy? Choices: - erosion - hydro - evaporation - thermal A:
Ans: thermal

Ques: Answer the following question given this paragraph: The convection zone is where convection takes place. It is located outward from the radiative zone. Q: What zone is outside the radiative zone? Choices: - diffusion zone - activation zone - peripheral zone - convection zone A:
Ans: convection zone

Ques: Answer the following question given this paragraph: When plants and other organisms die, decomposers break down their remains. In the process, they release nitrogen in the form of ammonium ions. This process is called ammonification. Nitrifying bacteria change the ammonium ions into nitrites and nitrates. Some of the nitrates are used by plants. The process of converting ammonium ions to nitrites or nitrates is called nitrification. Still other bacteria, called denitrifying bacteria, convert some of the nitrates in soil back into nitrogen gas in a process called denitrification. The process is the opposite of nitrogen fixation. Denitrification returns nitrogen gas back to the atmosphere, where it can continue the nitrogen cycle. Q: What process is the opposite of nitrogen fixation? Choices: - digestion - respiration - percolation - denitrification A:
Ans: denitrification

Ques: Answer the following question given this paragraph: 2.2 Water Water has many properties that are critical to maintaining life. It is polar, allowing for the formation of hydrogen bonds, which allow ions and other polar molecules to dissolve in water. Therefore, water is an excellent solvent. The hydrogen bonds between water molecules give water the ability to hold heat better than many other substances. As the temperature rises, the hydrogen bonds between water continually break and reform, allowing for the overall temperature to remain stable, although increased energy is added to the system. Water's cohesive forces allow for the property of surface tension. All of these unique properties of water are important in the chemistry of living organisms. The pH of a solution is a measure of the concentration of hydrogen ions in the solution. A solution with a high number of hydrogen ions is acidic and has a low pH value. A solution with a high number of hydroxide ions is basic and has a high pH value. The pH scale ranges from 0 to 14, with a pH of 7 being neutral. Buffers are solutions that moderate pH changes when an acid or base is added to the buffer system. Buffers are important in biological systems because of their ability to maintain constant pH conditions. Q: An excellent solvent that holds heat well and allows hydrogen bonds, what substance has many properties critical to life? Choices: - liquid - blood - plasma - water A:
Ans:
water