Understanding Electricity: The Baseball Analogy

Key Concepts

• Voltage: How fast the baseball is moving; speed of the electrical charge.
• Amperage (Amps): How much the baseball weighs; amount of electrical charge.
• Watts: How fast the baseball speeds up when you hit it; rate of energy transfer.

Historical Context of the Watt

• James Watt:
  • Credited with inventing the steam engine, building upon earlier innovators like Vitruvius, Heron, Taqi al-Din, and Thomas Savery & Newcomen.
  • Worked at University of Glasgow in 1773.
  • Sold giant engines for pumping water by 1776.
  • The unit of power, the watt, was named after him in 1908.

Power vs. Energy

• Energy: The ability to perform work.
• Power: The rate at which work is done.
• Differences are crucial—don’t confuse potential with rate of doing work.

Mechanical Watt

• Defined as mass times acceleration due to gravity times height, divided by time to lift the object.
• Examples:
  • Takes 1 watt to maintain a velocity of 1m/s against 1 Newton.
  • A 200 lb person climbing 10 ft in 5 seconds uses about 500 watts.

Electrical Watt

• Defined when 1 amp flows across a potential difference of 1 volt.
• Volt-Ampere: Almost a watt but involves power factor.

Important Principles

• DC Power: Volts x Amps = Watts.
• Voltage and Current Relationship:
  • 1 volt at 1,000 amps is equivalent to 1,000 volts at 1 amp.
  • Increased voltage enables transmission of power across great distances with thin wires.

Summary

• Cranking up voltage in power grids allows efficient power distribution with smaller wires.
• Understanding these principles is essential for working with electricity effectively.