Expressions Of Pj Problems

Pj Problems - Overview

Celestial Stars

The Number Line

Geometries

7 Spaces Of Interest - Overview

Triadic Unit Mesh

Creation

The Atom

Survival

Energy

Light

Heat

Sound

Music

Language

Stories

Work

States Of Matter

Buoyancy

Nuclear Reactions

Molecular Shapes

Electron Configurations

Chemical Bonds

Energy Conversion

Chemical Reactions

Electromagnetism

Continuity

Growth

Human-cells

Proteins

Nucleic Acids

COHN - Natures Engineering Of The Human Body

The Human-Body Systems

Vision

Walking

Behaviors

Sensors Sensings

Beauty

Faith, Love, Charity

Photosynthesis

Weather

Systems

Algorithms

Tools

Networks

Search

Differential Calculus

Antiderivative

Integral Calculus

Economies

Inflation

Markets

Money Supply

Painting

Calculating Capacity Of An Electric Water Heater

A family of four uses two tubs, one dishwasher, and one clothes washer in their home. Suppose an electric water heater supplies the hot water for the usage points. Determine:
**(a)** The usage points for this home
**(b)** The gallon capacity for the usage points
**(c)** The ratiing of the heating elements of the electric water heater
**(d)** The current flowing through the heater
**(e)** The correct-size wire to use when the electric water heater is installed.

**The strings**:
S_{7}P_{3}A_{32} (force - push).
**The math**:

Pj Problem of Interest is of type *force* (push).
**(a)** Usage point is calculated by assigning one usage point per person in the home, and one usage point for point of usage of hotwater in the home (bathtub/shower, dishwasher, clothes washer, etc). The total usage points is used to determine the amount of water in gallons from a usage points table.

So, 4 members of the family = 4 usage points

2 tubs, 1 dishwater, 1 clothes washer = 4 usage points

So, total usage points = 8 usage points.
**(b)** a typical usage points table is as follows:

Usage Points | Gallons Of Water |

4 or less | 40-galon water heater |

5 or 6 | 50-gallon water heater |

7 or 8 | 65-gallon water heater |

9 or more | 80-gallon water heater |

So, from usage points table, water heater for the home will have a 65-gallon capacity.
**(c)** A standard 65-gallon water heater has its heating elements rated at 4,500 watts and 240-volt AC wiring.
**(d)** If P = 4500 W, and V = 240 volts I = 4500/240 = 18.75 A.
**(e)** Wire diameter, current capacity, volts, and power table. Continuous load assumed.

American Wire Guage | Ampacity (current capacity) | Volts - Wattage |

18 | 7 Amperes | 24 Volts - 134 Watts |

16 | 10 Amperes | 24 Volts - 192 Watts |

14 | 15 Amperes | 120 Volts - 1,440 Watts |

12 | 20 Amperes | 120 Volts - 1,920 Watts; 240 Volts - 3,840 Watts |

10 | 30 Amperes | 120 Volts - 2,880 Watts; 240 Volts - 5,760 Watts |

8 | 40 Amperes | 240 Volts - 7,680 Watts |

6 | 60 Amperes | 240 Volts - 9,600 Watts |

Calculated current I = 18.75 Amperes.

So, from the wire-gauge table, a 12-gauge wire can carry 20 amperes. Since the calculated current is less than 20, it would seem appropriate to select a 12-gauge wire. However, the wattage rating of the electric water heater is 4,500 watts which is significantly more than the 3,840 watts of the 12-gauge wire. So a 10-guage wire is the appropriate wire to use when the electric water heater is installed.

Math

The *point* **.** is a mathematical abstraction. It has negligible size and a great sense of position. Consequently, it is front and center in abstract existential reasoning.

Derivation Of The Area Of A Circle, A Sector Of A Circle And A Circular Ring

Derivation Of The Area Of A Trapezoid, A Rectangle And A Triangle

Derivation Of The Area Of An Ellipse

Derivation Of Volume Of A Cylinder

Derivation Of Volume Of A Sphere

Derivation Of Volume Of A Cone

Derivation Of Volume Of A Torus

Derivation Of Volume Of A Paraboloid

Volume Obtained By Revolving The Curve y = x^{2} About The X Axis

Single Variable Functions

Absolute Value Functions

Conics

Real Numbers

Vector Spaces

Equation Of The Ascent Path Of An Airplane

Calculating Capacity Of A Video Adapter Board Memory

Probability Density Functions

Boolean Algebra - Logic Functions

Ordinary Differential Equations (ODEs)

Infinite Sequences And Series

Introduction To Group Theory

Advanced Calculus - Partial Derivatives

Advanced Calculus - General Charateristics Of Partial Differential Equations

Advanced Calculus - Jacobians

Advanced Calculus - Solving PDEs By The Method Of Separation Of Variables

Advanced Calculus - Fourier Series

Advanced Calculus - Multiple Integrals

Production Schedule That Maximizes Profit Given Constraint Equation

Separation Of Variables As Solution Method For Homogeneous Heat Flow Equation

Newton And Fourier Cooling Laws Applied To Heat Flow Boundary Conditions

Fourier Series

Derivation Of Heat Equation For A One-Dimensional Heat Flow

Homogenizing-Non-Homogeneous-Time-Varying-IBVP-Boundary-Condition

The Universe is composed of *matter* and *radiant energy*. *Matter* is any kind of *mass-energy* that moves with velocities less than the velocity of light. *Radiant energy* is any kind of *mass-energy* that moves with the velocity of light.

Periodic Table

Composition And Structure Of Matter

How Matter Gets Composed

How Matter Gets Composed (2)

Molecular Structure Of Matter

Molecular Shapes: Bond Length, Bond Angle

Molecular Shapes: Valence Shell Electron Pair Repulsion

Molecular Shapes: Orbital Hybridization

Molecular Shapes: Sigma Bonds Pi Bonds

Molecular Shapes: Non ABn Molecules

Molecular Orbital Theory

More Pj Problem Strings