9 клас. ЛР № 5. Визначення фокусної відстані та оптичної сили тонкої збиральної лінзи

The video outlines a laboratory exercise for ninth-grade students focused on determining the Focal Length and Optical Power of a thin Converging lens. The following scientific concepts and methodologies are presented:

Scientific Concepts:

• Focal Length: The distance from the lens to the point where light rays converge.
• Optical Power: The ability of a lens to converge or diverge light, calculated using the formula D = 1/F, where D is the Optical Power and F is the Focal Length.

Methodology:

1. Equipment Needed:
   • Converging lens
   • Demonstration handkerchief
   • Screen
   • Candle
   • Matches
2. Safety Precautions: Follow safety rules in the physics classroom.
3. Experiments:
   1. Experiment 1:
      • Obtain a clear image of a distant object (e.g., a window) on the Screen.
      • Measure the distance from the lens to the Screen (this is the Focal Length).
      • Convert this distance into meters.
      • Calculate the Optical Power using the formula D = 1/F.
   2. Experiment 2:
      • Place the Candle at a distance greater than twice the Focal Length.
      • Move the Screen to form a clear image of the Candle flame.
      • Measure distances from the Candle to the lens and from the lens to the Screen.
      • Calculate the Focal Length and Optical Power.
      • Construct and characterize the image.
   3. Experiment 3:
      • Place the Candle at a distance greater than the Focal Length but less than twice the Focal Length.
      • Repeat the process of obtaining a clear image, measuring distances, calculating Focal Length and Optical Power, and characterizing the image.
      • Record the measurement results in a table.
      • Compare the values of Focal Length and Optical Power across the three experiments.

Researchers/Sources Featured:

• None specifically mentioned in the subtitles.