The class started with a brief review of static electrical theory which was covered in the last few classes. The definition of a charged object and the various ways to charge a substance was discussed. Coulomb's law was then discussed in detail and the mathematical equation written. Each item in the formula was explained and then the electrical force compared to the gravitational force, the formulas being very much alike. The strength difference between the two was stressed, with hydrogen atoms being used as the example to show the gravitational force strength compared to the electrical force strength.
Assignment
study for lens test
Session Minutes
60
Minutes Student Attended
60
Lesson Comments
Olivia has a good background in chemistry, so it was easy to discuss the charges on atoms and the transfers of electrons to give the charge. As usual, he notes are impeccable.
Compare the force of gravity and the force of electrical attraction (repulsion).
review the inverse square law regarding gravitational attraction and compare it to the inverse square law of electrical attraction. Outline Coulomb's law and write the formula as force of attraction = proportionality constant x product of charges / distance squared. Define the SI unit of charge as a Coulomb and that it is equal to 6 x10n18 electrons. List k as 9 x 10n9 Nmn2/Cn2 Given the charges and the distance between electrons in hydrogen atoms solve for the electrical force in Newtons. Given the mass of the electrons, solve for the gravitational force and compare both.
Session Minutes
60
Minutes Student Attended
0
Lesson Comments
Lesson wil be given on Wed. Olivia was not present
We started with a brief review of conductors, insulators and why electrons move more easily through conductors. We proceeded to transfer of electrons resulting in a matter becoming charged, not proton movement. A whiteboard demonstration of charging by conduction was demonstrated using a charged rubber rod and an electroscope. Charging by induction was shown and the two methods compared and differentiated.
Through a series of demonstrations using plastic rulers, bits of paper, electroscope, foam cups, and balloons, show that neutral matter can be charged. Describe how the matter becomes charged, by the addition or subtraction of electrons. Discuss the makeup of the atom and that it is the electrons which have the ability to migrate. Illicit that the force of gravity is easily overcome by the force of the charged particles and stress that the charges are not permanent like gravity, but will dissipate over time. Introduce the concept of distance effect on the attraction/repulsion of charged particles, and that the effect of the charge is dependent on the distance. Review that like charges repel while unlike charges attract.
Session Minutes
60
Minutes Student Attended
60
Lesson Comments
Since Olivia has already taken a chemistry course, it was not needed to go into great detail regarding atomic structure, which allowed us to proceed a bit quicker.
We began the lesson by reviewing the definition of a lens, the effect that a lens has on light, the types of lenses, parts of a lens and lens diagram. Using pictures of the human eye, describe and explain the main anatomical parts of the eye, concentrating on the cornea and lens, which effect the diffraction of light. Explain the function of the retina in converting light energy into nerve electrical energy for transmission through the optic nerve to the optic center of the brain. Show that the image formed on the retina is inverted, but that the brain reverses it to upright. Using the diagrams of the eye, show how an image can be formed in front of the retina or behind it. Use the desktop lens kit to show how the focal point can be lengthened or shortened using the proper type of lens in front of the cornea.
Images formed by the eyes refraction of light was sketched on the board. Nearsighted and farsighted imaging formation was shown along with correction by lenses. The formation of an image using a candle, concave lens, screen and meter stick was used to demonstrate the types of images formed at different focal lengths
lenses-image formation in convex and concave lenses
Lesson Outline
Using a convex lens, candle,meter stick, and holders for the lens and candle. A large white card acts like a screen and the candle is placed at different lengths from the lens. The type of image is noted and the distance. the Focal point is determined. Using a diagram of the eye, we can show how corrections can be made for nearsighted and farsighted conditions
