PROBLEM: Do people focus differently using the same objective on the microscope?

PREDICTION:

MATERIALS: reflecting microscope, ruler, 5 objects, lens, index card

PROCEDURE:

EXERCISE I. Find the optical element-image distance. Using a convex lens and a source of light (near a window), create an inverted image. Look at diagram below. Measure the distance from the inverted image (or index card) to the lens. Record your answer and compare it with the image your partner found.

YOUR DISTANCE:  _____________       PARTNER’S DISTANCE: ____________

EXERCISE II. Look at 5 objects under the microscope. When each object is focused, measure the distance from the object to the objective. Record the focal distance in the graph below. Compare with 2 other groups and see if the focal distance is the same or not. Write your observations under the conclusions.

CONCLUSIONS: Is the focal distance the same for all objects? How did you prove this?