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Force probes are versatile tools in the physics lab, but their internal workings can introduce artifacts when measuring rapidly changing forces. The Dual-Range Force Sensor by Vernier uses strain gage technology to measure force, based on the bending of a beam. Strain gages along the length of the beam change resistance as the beam bends. The elasticity of the beam leads to oscillations that persist after being excited by an impulsive force. How quickly the force probe freely returns to zero is thus related to the rigidity of the beam and the total mass attached to it. By varying the added mass and measuring the resulting frequency of the probe's internal free oscillations, the effective mass and spring constant of the probe's moveable parts can be found. Weighing of the probe parts and conducting a Hooke's law experiment provide static verification of these parameters. Study of the force sensor's behavior helps students to learn about damped harmonic motion, mathematical modeling, and the limitations of measuring devices.

Discusses the movements of energy among different parts of the variable-gap capacitor system. Explanation behind the factor of one-half from a parallel-plate capacitor; Use of simple apparatus in investigating the force between capacitor plates; Comparison between the stored energy and application of a capacitor.

Discusses the history of the candela. Measurement techniques; Importance of candela; Former standards of luminous intensity; Determination of the luminous intensity of a light source using a human observer.

Focuses on the automatic shutoff sensing mechanism of gas pump nozzle. Application of the Bernoulli principle in the design of the automatic shutoff gas pump nozzle; Mechanism of the gasoline-pump nozzle manufactured by OPW company.

Studies the use of acceleration in lugging a garden hose and how it can be used in teaching physics. How accelerating water pressure in a hose can be achieved; How shrinkage and longitudinal disturbances can affect the flow rate of water.

Demonstrates an experiment that turned lightbulbs on at different times in a series circuit. Procedures for conducting the experiment; Observations on the bulb connections; Explanation for the the delayed flow of current on the last bulb.

Presents a look at the low-friction rotating platform, which was constructed by the use of the water pump from a 1979 Ford 302 V8 engine. Use of the device by physics' students; Purpose for which the device is used.