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PHYS199M

  • C8-01: GIANT PENDULUM

    C8-01
    Demonstrates conservation of energy
    The instructor backs up against the ladder/plywood backdrop, holds the pendulum bob up to his or her chin, and releases it. Because of conservation of energy the bob will swing across the stage and return to its original position adjacent to the instructor's chin, but without hitting his or her chin. Despite the wariness of the students, the pendulum bob cannot rise to a height greater than its original height, and the instructor is safe. Demo requires a minimum of 24 hours notice to prepare mounting cable. E-mail Lecture-Demonstration the day before to ensure that cable is ready.
    C8, OS11

  • K1-14 OSCILLOSCOPE CRT - DEFLECTION BY MAGNET

    K1-14
    Demonstrates the force on an electron beam by a magnetic field
    The beam of an oscilloscope CRT is viewed at the front on the fluorescent screen in the standard way. Holding a magnet near the CRT such that the magnetic field is perpendicular to the path of the electrons creates a magnetic force on the electron beam which deflects the beam, as can be seen on the fluorescent tube.
    K1

  • K1-15: OSCILLOSCOPE CRT - DEFLECTION BY ELECTRIC FIELD

    K1-15
    Demonstrate the deflection of an electron beam by an electric field.
    The electron beam starting at the rear of the tube is seen on the front fluorescent screen in the standard way. Applying an electric field on either of the two sets of internal deflection plates causes either horizontal or vertical deflection of the beam.
    K1

  • N2-02: DIFFRACTION SPECTRA - THREE SOURCES - EXPENDABLE GRATINGS

    N2-02
    Demonstrate diffraction spectrum of white light along with line spectra of mercury and cadmium.

    Three sources are permanently mounted on a roll-around cart, from top to bottom: (1)a clear glass long-filament incandescent light bulb which produces a continuous white light spectrum, (2) a mercury lamp which produces a line spectrum, and (3) a cadmium lamp which produces a line spectrum

    These spectra are seen using 1"x2" sections of a large roll of replica diffraction grating material with 13,200 lines per inch. The pieces of grating material are relatively cheap, and may be given to the students. Tell your students to go away and look at the spectra of various lights.

    The three lamps are mounted in a vertical line so the colors of the lines are the same as those in the adjacent white light spectrum. Point out that the spectra of mercury and cadmium are very different, and generalize that observation to suggest uniqueness of the spectra for each material.

    N2, OS3

  • P4-01: Radiation Monitor (Geiger Counter)

    P4-01
    Demonstrates radioactivity, the Radiation Monitor (Geiger Counter), and some differences between alpha, beta, and gamma radiation

    Radioactive mineral sources can be examined.

    Alpha particles have a range in air of about 2 or 3 cm; you must place the source close to the Radiation Monitor to observe the alphas. Inserting a piece of paper in the alpha beam stops them! Beta particles have a longer range in air, and are mostly unaffected by passing through a piece of paper. A thin lead sheet stops the betas, but some counting may remain due to the presence of a some gammas in the beta source. Gammas are unaffected by the paper or the thin lead sheet, but can be stopped by a lead brick
    SU19