Today we figured out from our data and the graph shown below just how much electric charge an electron possesses: -1.6 x 10^-19 C. Here's the graph: Thanks for all who contributed to this graph, especially Allison G, Clark B, and Kayley Z.
Assignment:
We worked to suspend the oil droplets in our simulation of Millikan's Oil Drop Experiment. In addition, we used spreadsheets to do a lot of the calculating for us. We have not corralled our data in order to try to determine the size of the charge on an electron. We should complete this mission tomorrow.
Assignment:
We are ready to figure out the amount of charge possessed by electrons using the Millikan Simulation. In order to do so, we will find the size of the electric charge possessed by oil drops in the simulation. The oil drops are generally charged, because it is easy for them to gain or lose a few electrons when squirted, or even when a cosmic ray enables acquisition of charge.
So you should find as many different amounts of electric charge as you can. That will help us to find out how much charge a single electron contributes. And using a spreadsheet can make the calculations a breeze. Be ready to work tomorrow. It's work that resulted in a Nobel Prize for Millikan! We viewed a bit about the landing of Mars Insight on the surface of Mars. It landed yesterday, and it is an impressive accomplishment in engineering and science. We watched about 7 minutes beginning at about 45 minutes. We also answered the items on yesterday's handout. Next up: The Millikan experiment! The simulations are posted on the Chapter 17 web page.
Today we worked on "Electric Potential vs Position" for practice with our findings from last Tuesday's lab work.
Assignments:
We debriefed after our lab yesterday, and then we went to our Tribes! Early release, and away!
Today we mapped the potentials in an electric field created by parallel aluminum plates in a container with a little water in it. The purpose was to find out how the potential in this electric field depends on the position in that field.
Today we prepared for tomorrow's lab work. The purpose of our experiment is to find out how the potential created by two parallel aluminum bars depends on position around these bars.
We will use a power supply and a voltmeter to fulfill this purpose. To find how one variable depends on another, we will plot the dependent variable (here it is the potential that "depends") on the y-axis and the independent variable on the x-axis, as usual. It turns out that a spreadsheet can be a great way to make such a plot. So bring your computers if you wish to put them to use! The stars of Physics II today were E, the strength of an electric field, and V, electric potential. We set up an analogy with ideas from gravitational force and gravitational potential energy to describe two important features of electric fields. Gravitational Force on massive object due to a gravitational field Electric Force on charged object due to an electric field Gravitational Potential We define the gravitational potential V (or, for brevity, just the potential) as the amount of gravitational potential energy stored per unit "gravitational charge" (aka "mass"). Potential is a property of a place within a gravitational field. Each place in a field has its potential. The units of gravitational potential are Joules / kilogram. Electric Potential Electrical potential is a potential energy load factor. It tells us how many joules of EPE are associated with each Coulomb of charge. Potential is a property of a place within an electric field. Each place in a field has its potential. The units of electric potential are Joules / Coulomb, which is also called a "volt." Assignments:
We finished up our dealings with static electricity today, namely Ch 16 Assignment 1. It will be checked next Monday.
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Physics IIMr. Swackhamer Archives
May 2019
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