Physics Chapter 1: Measurements

Course Content

• The course covers seven chapters
• Chapter 1: Physical Quantity, Units and Dimensions (2 weeks)
• Chapter 2: Motion in one Dimension (2 weeks)
• Chapter 3: Vector Analysis (2 weeks)
• Chapter 4: Waves, Oscillations and Sound (2 weeks)
• Chapter 5: Light, Lenses and Mirrors (2 weeks)
• Chapter 6: Heat and Thermodynamics (2 weeks)
• Chapter 7: Electricity & Magnetism (2 weeks)

Chapter 1: Physics and Measurements

• Topics:
  • Standards of length, mass, and time
  • Density and atomic mass
  • Dimensional Analysis
  • Conversion of units
• Physical Quantities: Force, velocity, volume, and etc are discussed
• Mechanics Basic Quantities: Length (L), Mass (M), Time (T)

1.1 Standards of Length, Mass, and Time

• Length: The standard of length is based on the speed of light in a vacuum, defined as 299,792,458 meters per second.
• Mass: The standard of mass is based on a specific Pt-Ir alloy cylinder (platinum-iridium alloy).
• Time: The standard of time is based on the atomic clock, specifically the characteristic frequency (period of vibration) of radiation from the Cs133 atom, defined as 9,192,631,770 oscillations per second.

1.3 Density and Atomic Mass

• Density: Mass per unit volume (p = m/V)
• Aluminum (Al): Density is 2.7 gm/cm³
• Lead (Pb): Density is 11.3 gm/cm³
• Atomic mass differences account for density differences between materials.
• Atomic spacing and arrangement in materials also affect density.

1.4 Dimensional Analysis

• Dimensions: Physical nature of a quantity
• Basic quantities in mechanics: Length (L), Mass (M), Time (T)
• Examples:
  • Area [A] = L²
  • Volume [V] = L³
  • Velocity [v] = LT⁻¹
  • Acceleration [a] = LT⁻²
  • Momentum [P] = MLT⁻¹
  • Kinetic Energy [KE] = ML²T⁻²
  • Potential Energy [PE] = ML²T⁻²

1.5 Conversion of units

• Converting units between different systems (e.g., cgs, mks, British Engineering)
• Examples provided for mile to meter, feet to meters and inch to meters conversions.
• Example calculation provided for determining the density (in SI units) of a cube given its mass and edge length.

Additional Problems and Examples

• Example 1.1: Determining the number of Aluminum atoms in a solid cube.
• Problem 7: Calculating the mass of an iron atom (given the molar mass).
• Problem 15: Identifying dimensionally correct equations.
• Problem 17: Determining the units of the universal gravitation constant (G).
• Pendelium Calculation Example: Demonstrating that the equation provided for the period of a pendulum corresponds correctly with all involved dimensions.
• Several practice examples are available for each section (problems 5-7, 15, 17 in the lecture slides, in addition to example 1.1)

This quiz tests your understanding of the fundamental physical quantities, units, and dimensions covered in Chapter 1 of the physics course. Topics include standards of length, mass, time, density, atomic mass, and dimensional analysis. Get ready to assess your knowledge on these essential concepts!