Showing posts with label simple. Show all posts
Showing posts with label simple. Show all posts

Wednesday, May 23, 2012

Strength of Materials: Simple Stress

Simple Stress - is the intensity of force inside a solid material. The object is influenced that may lead to breakage or change on it's physical form. 

It is force per unit area, which is basically Pascal (Pa) Newton per square meter or Megapascal (MPa) which is Newton per square millimeter.

The stress is spread out in the entire cross-section of the item that reacts to the external force or load applied.

Different Kinds of Internal Forces:

  • Axial Force - pull and or push action that is perpendicular to the cross section. Pull represents tensile force that tends to elongate the subjected member while Push represents compressive force that tends to shorten the subjected member, load usually denoted as P.
  • Shear Force - total resistance to sliding the portion to one side of the exploratory section past the other in vertical or horizontal manner, usually denoted as Vx for horizontal shear force and Vy for vertical shear force.
  • Torque - twisting the member either clockwise, counterclockwise or both, usually denoted as T.
  • Bending Moments - resistance to bending the member about any axes, and are often denoted as M or Mx for moment about x-axis or My for moment about y-axis.
Studying material's strength is relevant to guarantee that the structure to be used will be safe against maximum internal forces that is produce by combining different kinds of loads. 

Saturday, March 17, 2012

Economics: Interest

Interest: amount of money earned by given principal money.
Borrower's Viewpoint - interest is the amount of money to be paid for the use of a borrowed capital.
Lender's Viewpoint - interest is the income generated by the capital that was lent.

  • Simple Interest - varies directly with time since it is computed after or at the end of the invested period
    • Ordinary Simple Interest - base on one banker's year
    • Exact Simple Interest - based on exact number of days of a year, which considers ordinary year of 365 days and leap years that have 366 days
Formula: Future Worth = Present Worth + Interest Earned 
(F = P + i)

  • Compound Interest - computed every end of each interest period which is called compounding interest and the interest is added to the principal (which is now interest plus principal) that will produce a bigger interest 

Formula: Future Worth = Present Worth (1 + Interest Earned) ^total number of compounding period 
(F = P [1 + i]^n)