Showing posts from August, 2017

SAT Physics Conventions and Graphing - Slope and Area

SAT Physics Conventions and Graphing - Slope and Area GRAPHING VARIABLES The graphing techniques of mathematics are used in science to compare dependent and independent variables. In mathematics, you are familiar with the traditional x- and y-coordinate axes. In science, the x-axis represents the independent variable and the y-axis represents the dependent variable. The value of the dependent variable depends upon the independent variable. Graphs are always tided so that the dependent variable is listed first, and the independent variable is listed second. As an example, a position versus time graph would have position (dependent variable) plotted on the y-axis and time (independent variable) plotted on the x-axis. Slope Slopes are very important and are often the key to answering many of the graphing questions on the SAT Subject Test in Physics. Slope is determined by dividing the rise (y-axis value) by the run (x-axis value). The trick is to look at the units written on the

SAT Physics Conventions and Graphing - Fundamental and Derived Units

SAT Physics Conventions and Graphing - Fundamental and Derived Units The fundamental metric units (SI units) in physics cover the basic quantities measured, such as length, mass, and time. The units measure a quantity and are given a unit name and symbol. Table 1.1 lists the fundamental quantities along with the unit names and symbols. Derived units are combinations of one or more of the fundamental units. Table 1.2 lists common derived units used in physics. Some questions on the SAT Subject Test in Physics may ask which units correctly belong to a specific quantity. An easy way to do this is to write out the principal formula for the quantity and then replace each variable on the right side of the equation with its unit symbol. There may be more than one correct answer including the unit symbol, other derived units, and fundamental units. For example, all of the following are correct ways to express units of energy: J, N • m, and kg • m 2 /s 2 . Derived Units The unit of fo

SAT Chemistry Introduction to Chemistry - Measurements and Calculations

SAT Chemistry Introduction to Chemistry - Measurements and Calculations MEASUREMENTS AND CALCULATIONS The student of chemistry, must be able to make good observations. Observations are either qualitative or quantitative. Qualitative observations involve descriptions of the nature of the substances under investigation. Quantitative observations involve making measurements to describe the substances under observation. The chemistry student must also be able to use correct measurement terms and the required mathematical skills to solve the problems. The following sections review these topics. SCIENTIFIC METHOD Although some discoveries are made in science by accident, in most cases, the scientists involved use an orderly process to work on their projects and discoveries. The process researchers use to carry out their investigations is often called the scientific method. It is a logical approach to solving problems by observing and collecting data, formulating a hypoth­esis,

SAT Chemistry Introduction to Chemistry - Energy

SAT Chemistry Introduction to Chemistry - Energy Definition of Energy The concept of energy plays an important role in all of the sciences. In chemistry, all physical and chemical changes have energy considerations associated with them. To understand how and why these changes happen, an understanding of energy is required. Energy is defined as the capacity to do work. Work is done whenever a force is applied over a distance. Therefore, anything that can force matter to move, to change speed, or to change direction has energy. The following example will help you understand this definition of energy. When you charge a battery with electricity, you are storing energy in the form of chemical energy. The charged battery has a capacity to do work. If you use the battery to operate a toy car, the stored energy is transformed into mechanical energy that exerts a force on the mechanism that turns the wheels and makes the car move. This process continues until the charge or stored energy

SAT Chemistry Introduction to Chemistry - Matter

SAT Chemistry Introduction to Chemistry - Matter Matter is defined as anything that occupies space and has mass. Mass is the quantity of matter that a substance possesses and, depending on the gravitational force acting on it, has a unit of weight assigned to it. Its formula is w = mg, where m is the mass of the substance and g is a gravitational constant. Although weight then can vary as the gravitational constant does, the mass of the body is a constant and can be measured by its resistance to a change of position or motion. This property of mass to resist a change of position or motion is called inertia. Since matter does occupy space, we can compare the masses of various substances that occupy a particular unit volume. This relationship of mass to a unit volume is called the density of the substance. It can be shown in a mathematical formula as D = m/v The unit of mass (m) commonly used in chemistry is the gram (g), and of volume (V) is the cubic centi-meter (cm 3 ), milli

SAT Physics Subject Test - Practice Test 3

SAT Physics Subject Test - Practice Test 3 Do not use a calculator. To simplify numerical calculations, use g= 10 m/s2. PART A Directions: In this section of the exam, the same lettered choices are used to answer several questions. Each group of questions is preceded by five lettered choices. When answering questions in each group, select the best answer from the available choices and fill in the corresponding bubble on the answer sheet. Each possible answer may be used once, more than once, or not at all. Questions 1-3: (A) Position (B)   Displacement (C) Speed (D) Velocity (E) Acceleration 1. The slope of a position-time graph.   2. The slope of a velocity-time graph. 3. The area bounded by the function, the x-axis, and the time interval in a velocity-time graph. Questions 4-6: (A) Electric field (B) Electric force (C) Electric potential (D) Electric potential energy (E) Capacitance 4. A scalar quantity that reflects the ability or tendency o