STUDY GUIDE FOR SECTION III

The course and, consequently, the tests emphasize problem solving. In order to solve problems one needs to master the underlying concepts and principles. This guide points out some of the basic terms, concepts, principles or laws. In addition, please review sample problems in you notes and the book. Solving the HW6 problems on eGrade should also help you greatly.

Ch. 7: Work, Energy,and Power 

Visit this website to learn the fundamentals about work, energy and power

Review you knowledge of vectors. You already know how to add and subtract vectors. To calcualte work you need to know how to calulate the "scalar" or "dot" or "inner" product of two vectors.

Given two vectors. e.g  A = 2.5i+ 5j - 2k and B = 4i +2j - 5k.     Be able to calculate the product A.B and the angle between them. 

Be able to state in words and mathematically the following terms:

     work, energy, gravitational & elastic potential energy, kinetic energy, total energy.

Be able to define the terms: Joule, Watt, horsepower, and erg

Be able to solve problems using the work-kinetic energy theorem (Change in K = W) .

     and the fact that W = - Change in U

Given force and displacement as vectors in 3D, be able to calculate work as the 'dot' or 'scalar' product.

       W = F·S = FS cos A

Given a variable force such as F(x) = -kx or F(r) = GmM/r2, you should be able to perform integration and calculate work and/or change in K or U.

Be able to calculate the power when work and time or change in energy and time are given or can be calculated..


 

(Ch. 8) The Principle of Conservation of Energy is very important,

( E = U + K = constant):

You should be able to relate work with change in potential energy (gravitational and elastic). You should be able to use the principle of conservation of energy to solve a variety of problems. i.e. you should master

             E Total = K1 + U1 = K2 + U2    

You should be able to discuss how a simple pendulum, a pole vaulter, a roller coaster, elastic springs illustrate the principle of conservation of energy.

You should be able to distinguish between conservative and non conservative forces and how they affect the conservation of energy

You should understand the significance of the famous formula E = mc2 and be able to list a few application that are relevant to E = mc2

You should be able to show at low speeds E = mc2 reduces to E = ½ mv2.

Ch. 9 Systems of Particles:  Center of Mass , Linear momemtum and collisions.

  1. Be able to calculate the center of mass (center of gravity) for particles with known (x,y,z) coordinates using summation formulas.
  2. Be able to calculate the CM for symmetrical geometric shapes and/ or solid objects. Refer to examples done in class.
  3. Be able to use Newton's 2ne law fro a system of particles
  4. Be able to calculate the linear momentum of a system of particles

  5. You should be able to define and calculate linear momentum.

    6 You should understand linear momentum and how it relates to force and Newton's 2nd law

    7 Be able to calculate impulse and average force during a collision.

    8You should be able to distinguish between elastic and inelastic collisions.

    9.    You should be able to use http://www.physicsclassroom.com/and (when appropriate)  the principle of  conservation of energy to solve collision problems in one and two dimensions.