Graphs are an important component in physics laboratory reports. We have noticed that our students have difficulty selecting the "scale" and the "starting value" for an axis while generating graphs on graph paper. Recommendations concerning convenient scales and starting values are found in textbooks, laboratory manuals, and…

Analysis of collisions is standardly included in the introductory physics course. In one dimension (1D), there do not seem to be any unusual issues: Typically, the initial velocities of the two colliding objects are specified, and the problem is to find the final velocities. In 1D there are therefore two unknown variables. One can write the…

The use of systems in many introductory courses is limited and often implicit. Modeling two or more objects as a system and tracking the center of mass of that system is usually not included. Thinking in terms of the center of mass facilitates problem solving while exposing the importance of using conservation laws. We present below three…

After learning how to trace the principal rays [Fig. 1(i)] through a thin lens in order to form the image in the conventional way, students sometimes ask whether it is possible to use other rays emanating from the object to form exactly the same image--for example, the two arbitrary rays shown in Fig. 1(ii). The answer is a definite yes, and this…

Problems on the dynamics of changing mass systems often call for the more general form of Newton's second law Fnet = dp/dt. These problems usually involve situations where the mass of the system decreases, such as in rocket propulsion. In contrast, this experiment examines a system where the mass "increases" at a constant rate and the net force…

A number of well-known hydrostatics problems dealing with Archimedes' principle concern a loaded boat floating in a pool. Examples of this sort of problem include: 1. (a) If a stone is thrown overboard from a boat floating in a pool, does the water level in the pool rise, fall, or remain unchanged? (b) If a hole is made in the bottom of the boat…

Laboratory sessions offer students an opportunity to develop creative problem-solving skills and to better understand the nature of the scientific process through hands-on learning. Unfortunately, traditional procedures are often written in such detail, they require students to do little more than follow step-by-step directions. Under those…

Discusses a high school laboratory in which the students take an active role in designing, implementing, and performing experiments concerning basic concepts in physics. (MLH)

An activity in which students design and build an apparatus that can be used to rapidly determine the specific gravities of small substances is described. Calculations needed to determine the density of substances when using the Jolly balance are included. (KR)

The use of computer spreadsheet programs in the physics laboratory is discussed. An example of this application with a conservation of energy laboratory is presented including the cases of a rolling sphere and a sliding sphere. (CW)

Describes an exercise designed for an introductory level calculus-based physics class. Presents a problem on why a rod dipped in water is stable when it is oriented at an angle with the vertical. Discusses qualitative understanding, mechanical understanding using equations, and experimental verification of the problem. (YP)

Described are four musical instruments constructed from polyvinyl chloride (PVC) pipe. The use of computerized synthesizers to play scales and chords is discussed. Suggestions for other illustrations of acoustics are included. (CW)

The effects of temperature and pressure on the collapsing of soda cans are discussed. The use of various temperatures and substances for the cooling bath are described. (KR)

Two different methods of measuring the temperature of an incandescent lamp at various voltage levels are described. By observing the color produced at a particular voltage levels, the lamp's color as a function of temperature can be determined. Needed equipment include a variac, a voltmeter, and an ammeter. (KR)