两道SAT2物理高频练习题.

2017-08-06 作者： 247阅读

　　下面澳际小编为大家搜集整理了两道SAT2物理高频练习题，希望能够帮助各位同学更好地备考SAT2物理考试。

　　1. A boy throws a ball straight up in the air and then catches it again. Which of the above graphs best represents the ball’s position with respect to time?

　　SAT2物理考试试题

　　Explanation

　　You can usually answer classification questions a bit more quickly than the standard five-choice completion questions, since you only need to review one set of answer choices to answer a series of questions.

　　The answer to the question is B. The ball’s position with respect to time can be expressed by the equation y = –1/2 gt2, where g is the downward, acceleration due to gravity. As we can see, the graph of y against t is an upside-down parabola. In more intuitive terms, we know that, over time, a ball thrown in the air will rise, slow down, stop, and then descend.

　　2. A gas in a closed container is steadily heated over a period of time. Which of the following statements is true of this process?

　　(A) The average kinetic energy of the gas molecules decreases

　　(B) The mass of the container increases

　　(D) The gas changes phase into a liquid

　　(E) The specific heat of the gas decreases

　　Explanation

　　The answer to this question is C. The key lies in remembering the ideal gas law: PV = nRT.

　　According to this formula, an increase in temperature is accompanied by an increase in pressure. A is wrong, since the average kinetic energy of gas molecules corresponds to their temperature: if the temperature increases, so does the average kinetic energy of the molecules. B is wrong because we’re dealing with a closed container: the mass cannot either increase or decrease. D is wrong because a gas must be cooled, not heated, to change phase into a liquid. Finally, E is wrong because the specific heat of any substance is a constant, and not subject to change. We’ll touch on all this and more in Chapter 9: Thermal Physics.

　　以上就是澳际小编对两道SAT2物理高频练习题的介绍，希望同学们通过阅读，对SAT2物理考试成绩提升有一定的帮助。如果同学们在备考中遇到其他问题，可以致电澳际在线留学专家。