DEPARTMENT OF PHYSICS

Professor F. N. Entwisle

Assoc. Prof. E. Smith

Mr. W. Hazell, Jr.

Mr. P. Nielsen

Mr. A. Zentgraf

The Department of Physics is in charge of the course in Physics given to Freshmen and Sophomores, and of the course in Strength of Materials given to Juniors.

It is the objective of the course in Physics to provide a knowledge of the fundamentals of the subject and to teach these fundamentals as prerequisite to later work in professional subjects rather than as basic principles in a discreet scientific subject. To this end the engineering aspects of the subject are stressed more than would be the case in General College Physics.

The schedule of instruction includes a rather small amount of formal lecturing with a large amount of informal recitation and problem work together with one afternoon each week spent in Laboratory. Effort is made to unify the instruction in the class room and in the laboratory. The work in the latter, which is largely quantitative, is designed to present fresh problems for the students’ solution as far as possible rather than to require routine rechecking of known constants.

The course in Strength of Materials is designed to present the fundamental causes of the strain in material under stress. Effort is made to present a course which may be of common benefit to each of the four professional departments in the College. Instruction is carried out by means of lectures and recitations and one-half day per week spent in the Laboratory. The laboratory is designed to demonstrate the theory presented in the class room and thus furnish visual evidence of the accuracy of theoretical assumptions.

The Physics Laboratory

The Physics Department is supplied with two laboratories, adequately equipped with standard and special apparatus for quantitative measurements in elementary mechanics, heat, sound, light, and electricity. Its furnishings include sensitive physical balances, acceleration apparatus, coincidence and compound pendulums, Young’s Modulus and centrifugal force apparatus, force tables, ballistic pendulums, microscopes, radiation equipment, and specially designed equipment for obtaining centers of gravity and moments of inertia of various specimens.

Equipment is at hand for performing standard experiments in heat. Kundt’s tubes, electric tuning forks and resonance tubes are provided for experiments in sound. Measurements in light employ diffraction gratings, prisms, lenses, and mirrors. A first class optical bench with Lummer-Brodhun head, 30″ sphere photometer, illuminometer, and Weston Photronic cells are used for illumination measurements. An equipment of meters, resistance units, Wheatstone bridges, potentiometer sets and traction permeameter is provided for elementary electrical measurements.

Strength of Materials Laboratory

The Strength of Materials Laboratory has been designed for the purpose of student instruction. With this in mind, the size of the apparatus has been kept within moderate limits so that the student may perform the test. The laboratory is housed in two adjoining rooms. The first room is equipped with:

1—100,000 lb Olsen Std. Tension Compression Test Machine.

1—50,000 lb Machine of the same sort.

1—50,000 lb hand operated Riehle Tension Compression Machine fitted with extra size screw for column work.

1—5000 lb Riehle Machine.

2—Punch Presses for shear studies.

2—Sets of Apparatus for testing Eccentric Riveted Joints.

1—Gyration Pendulum.

1—Polarized Light Stress Analyzer.

1—Torsion Demonstrator.

1—Slender Column Tester, also

Brinell Hardness Meter

Shore Scleroscope

Portable Brinell Tester

Extensometers, Strain Gauges, Shear Testers, for the above machines. Torsion Meter, Planimeters, etc.

In the second room the cement and concrete testing appliances have been concentrated, including:

1—Riehle Briquette Testing Machine

Concrete Cylinder Moulds

Concrete Beam Moulds

Vicat Needles

Briquette Moulds, etc.

Moist Storage Cabinet

Sand and Gravel Bins

1—Power Concrete Mixer

SUBJECTS OF INSTRUCTION in the DEPARTMENT OF PHYSICS

Phys 1 Introductory Problems in Physics.

An introductory course to familiarize the student with the best methods and procedure in performing calculations in Physics. Practice is given in the use of the slide rule, logarithms, mathematical and physical tables, construction of graphs and curves, co-ordinate and tabular ruled paper. Emphasis is placed upon the arrangement of work, efficiency of calculations and methods of attack. The question of precision is introduced through simple measurements and calculations and is emphasized throughout the work of the year. A set of problems has been compiled which aims to present the elementary principles of physics as basic to all engineering problems.

The work of the second term continues this approach, with special emphasis upon the proper preparation of reports in Physics. All of this work is done under conditions which approximate the environment of the engineering computing office.

Phys 2 and Phys 3. General Physics.

The objective of the courses in General Physics is a knowledge of the fundamental laws of physical science, visualized as the foundation for later professional work. To this end, the courses are administered from the Engineering rather than the Scientific viewpoint.

Phys 2.

Elementary Mechanics—Linear and curvilinear motion; simple force system; energy and power; static forces in fluids; simple harmonic motion.

The laboratory work which accompanies this course is entirely quantitative and is designed to aid, by physical demonstration the development of the concepts originated in the classroom. To this end, the laboratory experimental work follows as closely as possible after the classroom exercises so that the essential unity of the two may be impressed upon the student’s mind. An effort is made to develop the student’s capacity for sustained careful observation and deduction, and to initiate good practice in the matter of recording and reporting upon scientific and engineering data. Great stress is placed upon the precision of the results obtained in the laboratory.

Texts: “Physics”, edited by Duff; Entwisle, “Experiments in Mechanics”.

Phys 3

Heat, Electricity, Sound and Light.

Heat. Heat as a form of energy; calorimetry; expansion principles; heat transfer; meteorology.

Electricity. Fundamental principles of electric charge and electric current; development of essential mechanical nature of electrical and magnetic measurements.

Sound. Wave motion; propagation; principles of sound quality; acoustics of rooms.

Light. Illumination; photometry; principles of reflection; elementary geometrical optics; formation of spectra; interference; polarized light.

Laboratory work is given in the second semester of the course and covers a wide range of physical measurement, with particular attention given to the accuracy possible with the apparatus used.

Texts: “Physics”, edited by Duff; Entwisle, “Experiments in Heat, Sound, Light and Electricity”; Entwisle, “Elements of Sound and Light”.

Phys 30 Strength of Materials. Prerequisites: Math 21, Mech 20.

The object of a study of Strength of Material is:

First, to determine the relations between the external forces acting on a body and the internal forces or stress and between external forces and the deformations or strains, so that the stresses may be determined from known loads or from measured strains or the strains determined from known loads.

Second, to obtain a knowledge of those properties of engineering materials necessary to an understanding of these relations.

Among the topics covered are stress-strain curves, properties of engineering materials, thin-walled cylinders, riveted joints, combined stresses and strains, torsion, statically determinate and statically indeterminate beams, shear diagrams, moment diagrams, elastic curves, flexure formula, Euler column formula, Gordon-Rankine formula, straight line column formula, repeated loads, fatigue of metals, impact and energy loads, stresses in flat plates, and reinforced concrete beams.

An introduction to the use of a handbook is accomplished by instruction in the A. I. S. C. handbook and by the assignment of special problems for solution in class under supervision.

In the laboratory, tests are performed to verify the theoretical considerations studied in the classroom work. These include a study of testing machines, tension test of metal, test of riveted joint, compression tests, Brinell hardness, wood tests, strength of cement and mortar, concrete in bond and tension, construction and test of a reinforced concrete beam, slender column tests, torsion in shafts, and stress analysis by means of polarized light.

Texts: Frost, “Laboratory Manual”; Seely, “Resistance of Materials”; A. I. S. C. Handbook.