Mastering Physics Without a Calculator

Aug 6, 2024

Review flashcards

How to Solve Physics Without a Calculator

Introduction

  • Tips to improve time, speed, efficiency, and marks in physics.
  • Focus on solving numericals without a calculator.

Key Concepts

Indices (Powers)

  1. Multiplication Rule:
    • For numbers:
      • If x^a * x^b = x^(a+b)
  2. Division Rule:
    • If x^a / x^b = x^(a-b)
  3. Power of a Power Rule:
    • (x^a)^b = x^(a*b)
  4. Roots Representation:
    • x^(1/2) = √x
    • x^(1/n) = nth root of x

Powers of 10

  • Positive power means moving decimal to the right.
  • Negative power means moving decimal to the left:
    • Example: 8 x 10^4 = 80000
    • Example: 8 x 10^-4 = 0.0008

Standard Units and Prefixes

  • Importance of knowing standard units for conversions:
    • Length - Meter
    • Weight - Kilogram
  • Example of converting nanometers to meters: 20 nm = 20 x 10^-9 m

Practical Problem Solving

Example Calculation Without a Calculator

  • Convert 0.2 / 8 x 100:
    1. Convert 0.2 into scientific notation.
    2. Simplification leads to an answer of 2.5.

Perfect Squares

  • Memorize perfect squares from 1 to 20.
  • Use perfect squares for calculations involving pi (π = 3.14).

Physics Example: Second Pendulum

  • Formula: T = 2π√(L/g)
  • Rearranging gives L = (T^2 * g) / (4π^2)
  • Substituting values yields an approximate length of 1 meter.

Division by Zero

  • Remember: Any number divided by 0 is infinity.
  • Any number divided by infinity is 0.

Trigonometric Functions

Common Values to Memorize

  • Sin θ, Cos θ, Tan θ Values:
    • Sin 0 = 0; Sin 30 = 1/2; Sin 45 = 1/√2; Sin 60 = √3/2; Sin 90 = 1
    • Cos 0 = 1; Cos 30 = √3/2; Cos 45 = 1/√2; Cos 60 = 1/2; Cos 90 = 0
    • Tan θ = Sin θ / Cos θ

Example Problem Using Trigonometric Values

  • Given initial velocity, acceleration, and time, calculate final velocity using:
    • Vf = Initial + (Acceleration × Time)

Conclusion

  • Practice these concepts regularly to improve in physics.
  • Keep revising standard units and trigonometric values.

Next Steps

  • Solve practice problems and apply the tips learned.
  • Engage with the material and seek further resources if needed.