Kinematics Overview Presentation Notes

Introduction

• Focus on kinematics for AP Physics 1, high school, and introductory college courses.
• Six main areas: terms, calculations, strategies, ideas.

Terminology

Scalar vs. Vector

• Scalar: Only magnitude (e.g., time, speed, distance). Always positive.
  • Speed: Distance/Time (m/s).
  • Units: Time in seconds, speed in m/s, distance in meters.
• Vector: Magnitude and direction (e.g., velocity, displacement, acceleration). Can be positive or negative.
  • Velocity: Displacement/Time, can be positive or negative.
  • Displacement: Final position minus initial position (meters).
  • Acceleration: Change in velocity over time (m/s²).

Constant Motion

• Constant velocity: Same displacement per time.
• Key formula for constant velocity:
  • ( \Delta x = V \times t )
  • ( \Delta X/t = V )
• Balanced forces mean constant velocity.

Graphs

• Position vs. Time:
  • Flat line = at rest.
  • Positive slope = moving away.
  • Negative slope = moving towards origin.
• Velocity vs. Time:
  • Horizontal line = constant velocity.
• Acceleration vs. Time:
  • Always zero for constant velocity.

Acceleration

• Rate of velocity change per time (m/s²).
• Ways to accelerate:
  • Speeding up, slowing down, changing direction.
• Graphs:
  • Curving lines indicate acceleration.

Formulas

• ( V = V_0 + at )
• ( x = x_0 + V_0t + \frac{1}{2}at^2 )
• ( V^2 = V_0^2 + 2a\Delta x )

Problem Solving Strategy

1. Label known and unknown variables.
2. Draw a diagram with variables and directions.
3. Use algebra to isolate unknown variables.

Free Fall Motion

• Only affected by gravity (( g = -9.8 \text{ m/s}^2)).
• Rules:
  • Rising: Slowing down.
  • Peak: Instantaneous velocity of 0 m/s.
  • Falling: Speeding up.

Projectile Motion

• Two-dimensional motion; horizontal motion constant.
• Components:
  • Horizontal velocity (( V_{0x} = V_0 \cos \theta ))
  • Vertical velocity (( V_{0y} = V_0 \sin \theta ))
• Problem Solving:
  • Make X and Y columns for values.
  • Time is a shared value between X and Y analysis.
  • Use vector addition for final velocity.

Calculating Angles

• Use inverse trigonometry to find angles.
• Example: Inverse tangent for angle calculation.

Conclusion

• Detailed review of kinematic concepts, problem-solving approaches.
• Important for understanding physics problems and exams.