Prep.2 Unit One - Lesson One

Oscillatory Motion

• Oscillatory motion involves a body moving back and forth around a rest position.

• Characteristics of oscillatory motion:

  • Motion is repeated at equal time intervals.

  • Displacements around the rest position are equal.

  • Maximum velocity occurs at the rest position, decreasing to zero at maximum displacements.

Key Concepts

• Definition of Oscillatory Motion:

  • The periodic motion of an oscillating body around its rest point, occurring in equal intervals of time.

• Relation between Velocity and Kinetic Energy:

  • Kinetic Energy (KE) is directly proportional to:

    • The mass of the oscillating body.

    • The square of the velocity.

  • An increase in velocity results in increased kinetic energy, assuming constant mass.

Periodic Motion

• **Periodic Motion: **

  • A motion regularly repeated at equal time intervals.

Examples of Oscillatory Motion

• The movement of springs is a classic example of oscillatory motion.

• Graphical representation shows oscillatory motion through the movement of a pencil on paper tape.

Properties of Oscillatory Motion

• Amplitude:

  • The maximum displacement from the rest position, measured in meters (m).

• Complete Oscillation:

  • When the oscillating body passes a fixed point two successive times in the same direction.

Important Terms

• Periodic Time (T):

  • Time taken for one complete oscillation.

• Frequency:

  • Number of complete oscillations made per second, measured in Hertz (Hz).

Formulas and Relations

• Calculating Periodic Time and Frequency:

  • Given Periodic Time = 0.2 sec;

    • This implies that the oscillating body completes one full cycle in 0.2 seconds.

  • Frequency of 20 Hz implies 20 complete oscillations in one second.

Inverse Relationship between Periodic Time and Frequency

• Frequency is the reciprocal of periodic time.

• Thus, frequency decreases as periodic time increases and vice versa.