PHY231B CORE LESSONS & OUTPUT SKILLS, Summer '99

CORE LESSONS & OUTPUT SKILLS

PHY231B, Summer '99

Vocabulary: potential energy curve, energy diagram, left and right turning points.

Given the graph of a one-dimensional potential energy function and the total energy of a particle, give a qualitative description of the motion of this particle and locate its turning points, if any, and regions of acceleration and deceleration.
Given a simple potential energy function for a particle, and the corresponding slope function (in one dimension or radially with spherical symmetry), sketch the function, determine the left and right turning points (if any) of the motion and, for any given position, the force acting on the particle and its acceleration and velocity.

Define mass and describe a method for determining the mass of an unknown object in terms of a standard mass.
Define weight and state at least two differences between mass and weight.

Determine the mass of an unknown object from experimental data describing its interaction with an object of known mass.
Given g, find an object's mass from its weight and vice versa.

Describe and sketch the essentials of the Cavendish balance, communicating clearly how the apparatus works.
Describe how the Cavendish experiment can be used to examine the validity of each of the three variables in Newton's law of gravitation.

Vocabulary: gravitational mass, inertial mass, active and passive gravitational mass, (generalized) tidal force.
Explain how Galileo's experiment and Newton's second law establish the proportionality of gravitational force to mass.
Outline the methods, actual and idealized, used to measure gravitational and inertial mass.
Give three examples where inertial forces come into play on you.
State: why Einstein suspected that inertial and gravitational forces were essentially the same; and to what level of precision they are known to be equivalent.
State one way you could tell that the Earth's pull was present if you were an astronaut orbiting the earth in a sealed capsule of finite size, and another way if you had a window.
State the objective of the Dicke-Eötvös experiment. Describe what is looked for in the behavior of the torsional penelulum and why.
Design a simple experiment that could be used to measure the local acceleration of gravity, g. Show that the velocity of the article being used is immaterial to the measurement.
Compare Einstein's Equivalence Principle (ignoring any limitations) with Newton's explanation, assuming the earth's gravity field is present.
State whether you believe Newton's third law is absolute and justify your belief.

Vocabulary: Doppler broadening, Doppler effect, Doppler shift.
Describe how the Doppler effect is used by astronomers and cosmologists to justify the "expanding universe" model.

Solve any Doppler shift problem by deriving the shift for that particular case (not by using the Doppler shift formula and not by deriving the general case and then using it).
Use the Doppler shift formula to determine the Doppler shift for given motions of a sound wave source and a receiver relative to each other as well as to the acoustic medium.
Given a value for the Doppler shift, calculate the relative speed between receiver and source.

Solve problems using: (a) the definition of of mass current; (b) I=ρ A v; (c) the steady-state condition; and (d) I=(p₁-p₂)/R.
For an incompressible fluid, entering and leaving a closed region by several channels, apply the steady-state condition to relate the average fluid speeds in these channels and quantities describing the cross-sectional areas of these channels.