. Measure the diameter of the quarter (object, ho) and record below.
2. Place your quarter (object) and lens so the diameter of the image the quarter on the screen is less then 1.5 cm. Make sure that the image is brought into sharp focus.
3. Measure the distance between the object and the lens (do). Record the value in the table below.
4. Measure the distance between the lens and the screen (di). Record the value in the table below.
5. Use the thin lens formula
, along with your measured values for do
to calculate the focal length of your lens. Record your values in the table below.
Hope this helps.