*Question*
Answer the following question given this paragraph: Some machines change the direction of the force applied by the user. They may or may not also change the strength of the force or the distance over which the force is applied. Two examples of machines that work this way are the claw ends of hammers and flagpole pulleys. You can see in the Figure below how each of these machines works. In both cases, the direction of the force applied by the user is reversed by the machine. Q: Claw ends of hammers and flagpole pulleys are examples of simple machines that reverse what? Choices: - direction of power - direction of work - direction of friction - direction of force A:
**Answer**
direction of force

*Question*
Answer the following question given this paragraph: Exocytosis describes the process of vesicles fusing with the plasma membrane and releasing their contents to the outside of the cell, as shown in Figure below . Exocytosis occurs when a cell produces substances for export, such as a protein, or when the cell is getting rid of a waste product or a toxin. Newly made membrane proteins and membrane lipids are moved to the plasma membrane by exocytosis. Q: What describes the process of vesicles fusing with the plasma membrane and releasing their contents to the outside of the cell? Choices: - autolysis - endocytosis - expulsion - exocytosis A:
**Answer**
exocytosis

*Question*
Answer the following question given this paragraph: Why does the pressure of a gas increase as it gets warmer? Particles of a gas are constantly moving and bumping into things. The force of the collisions is measured by pressure. Pressure is the amount of force exerted on a given area, such as pounds of force per square inch. When gas particles heat up and gain energy, they move faster. This causes more collisions and greater pressure. Therefore, heating particles of gas in a closed space causes the pressure of the gas to increase. Explore the behavior of gas particles at different temperatures at the following URL. Change the temperature of the gas and watch what happens to its particles. Q: If everything else stays the same in a system with a gas in it, and the gas gets warmer, what will happen to its pressure, generally? Choices: - it drops - it stays the same - it's eliminated - it increases A:
**Answer**
it increases

*Question*
Answer the following question given this paragraph: Chemistry is a branch of science. Although science itself is difficult to define exactly, the following definition can serve as starting point. Science is the process of knowing about the natural universe through observation and experiment. Science is not the only process of knowing (e. , the ancient Greeks simply sat and thought), but it has evolved over more than 350 years into the best process that humanity has devised to date to learn about the universe around us. The process of science is usually stated as the scientific method, which is rather naively described as follows: (1) state a hypothesis, (2) test the hypothesis, and (3) refine the hypothesis. Actually, however, the process is not that simple. (For example, I don't go into my lab every day and exclaim, "I am going to state a hypothesis today and spend the day testing it!") The process is not that simple because science and scientists have a body of knowledge that has already been identified as coming from the highest level of understanding, and most scientists build from that body of knowledge. An educated guess about how the natural universe works is called a hypothesis. A scientist who is familiar with how part of the natural universe workssay, a chemistis interested in furthering that knowledge. That person makes a reasonable guessa hypothesisthat is designed to see if the universe works in a new way as well. Here's an example of a hypothesis: "if I mix one part of hydrogen with one part of oxygen, I can make a substance that contains both elements. " Most good hypotheses are grounded in previously understood knowledge and represent a testable extension of that knowledge. The scientist then devises ways to test if that guess is or is not correct. That is, the scientist plans experiments. Experiments are tests of the natural Saylor URL: http://www. saylor. org/books. Q: Science is the process of knowing about the natural universe through observation and this? Choices: - Test - variation - experimental - experiment A:
**Answer**
experiment