Review Sheet for First Exam

PHYS 350 Spring 2013

Exam will be held during class on Thursday, 14 February. Expect about 2 essay or multi-part short answer questions and about 3 problems. No multiple choice, true-false, matching, etc. questions.

Some key concepts and items to review (I provide no guarantee that this is complete or that the exam will perfectly reflect what's on this list):

· Cause and nature of “exponential growth”. Relationships between population growth and growth in consumption of resources and energy production. Limiting factors to growth; how can we control (or stop) human population growth? You should be able to apply the compound interest formula, doubling times, and the exponential growth/decay formula to a large range of problems.

· What happens when a finite resource as it is consumed at a growing rate? How can we calculate how much time is left until the resource is depleted? In practice, what happens to the cost and production rate of the finite resource throughout the (short) history of its consumption?

· Definition and typical units for energy (Joules, foot-pounds, kilowatt-hours, etc.). What kind of "machines" allow us to convert between different forms (e.g. motor: electric->mechanical)?

· Newton’s laws of motion and gravity. Definitions of Force, Work, Power, etc. You should be familiar with units for these, both "metric" units and those in common practice. What is "torque"? If I give you a "force", can you calculate how much energy will be consumed moving something (e.g. a car) through a given distance? Given a mass and velocity, you definitely should be able to calculate how much kinetic energy is available. Given a mass and height, you should be able to calculate gravitational potential energy.

· There aren't very many types of natural forces that are useful for energy production (e.g., electromagnetic, nuclear, gravity). There are many that fight against us (friction, viscosity, wind drag, etc.). What is a "conservative" force? What is a non-conservative force? What is "conserved" (energy)?

· What are the different forms of internal energy, and how do these represent mechanical kinetic or potential energy (often at the microscopic level)? Can you cite a few examples of each? How do collisions drive a gas into thermal equilibrium, and how do all these various forms of internal energy interrelate in thermal equilibrium?

· We use energy for motion (mechanical energy) or heat (thermal energy), and we can convert between these (e.g. "heat engine"). Why can't we convert from thermal energy to mechanical energy with 100% efficiency? How do you calculate the maximum efficiency? If there are many inefficiencies in a system, how do you calculate the net efficiency (product of the individual efficiencies).

· "Heat" is the transfer of thermal energy FROM high temperature TO low temperature regions. Thermal energy can be transferred through conduction, convection, and radiation. Make sure you know what these mean and how each depends on the temperature difference. How can we maximize or minimize heat transfer in the real world?

· 1^st and 2^nd “Laws of Thermodynamics”. What do they mean (there’s no free lunch)? Specific Heat; Latent heat of fusion and vaporization; phase changes. You should be able to calculate how much heat (energy) is transferred to produce a given temperature change and how much heat it takes to change the "phase" of a substance (e.g. water).

· Basic properties of electromagnetic radiation in thermal equilibrium (e.g. Wien's Law; Stephan's Law; Planckian Brightness distribution)