Electric Field Lines and Flux

Flux as a Function of Surface Angle
We use the mechanical model, a protractor. We should measure the number of the lines, and then, we use the measure of the lines to calculate the the angle of degree and the radians.

Plot the flux as a function of radians. The graph showed the flux which was a curve. From the graph, we knew that the flux has relationship with the angle and radians.

The flux equals the dot product of the vectors of electric field  and the vector of the area. In other words, the flux equals the electric field multiply the area, and multiply cosine the angle between the electric field and the area.

This picture showed  the flux into or out of an oval and electric flux with two charges. From the activity, we knew if the area has flux, the flux must have a charge or more charges inside the flux.

Electrostatic Forces

Interactions of Scotch Tape Strips
Two 10 cm strips of Scotch tape on the table with the sticky side down. The end of each tape should be curled over to make a non-stick handle. Peel one tape off the table and bring the non-sticky side of the tape toward another strip. The two trips of tape on the table sticky side down and label them "B" for bottom. Press another strip of tape on top of each of the B pieces; label these trips "T" for top. Pull each pair of strips off the table. Then pull the top and bottom strips apart.

The picture showed the interaction between two top strips when they were brought toward one another, the interaction between two bottom strips, and the interaction between a top and a bottom strip.

Drawing a free body diagram for the ball being suspended at an angle. Using free boy diagram to derive an expression for the electrical force acting on the hanging ball. Using some trigonometry and measuring values to come up with a way of calculating angle, then using the New Calculated Column function of logger Pro to go from measuring values to a value for the electrical force acting on the hanging ball.  Let make the length is L and separation distance is X.

The picture showed the calculation of the electrical force and the body diagram.

Electric Force Law Video Analysis Activity

Note that you are seeing a ball and the lower part of a 2.00 m long string. The mass of the ball is 2.93 g. A charged ball on a stick being brought in horizontally toward the hanging ball. In this activity, we use the conclusion to calculate.

This graph showed that the charged ball of the whole video move direction and way. It was also showed the measure of the changed ball in the whole playing. 

CTEM Presentation and Poster Competition

From this presentation, I knew some information about engineer. It was interested in the 3D printer and the robot. The robot could up and down.

The Incredible Mass Lifting Machine

Developing A Mass Lifting Engine Cycle

This activity showed that a heated rubber band was fine if all we wanted to do was to move a weight once. We heated the rubber band at first, and then, waited several minute. The mass dropped on the desk, and turning off the heat gun.
The Incredible Mass Lifter Engine

The engine cycle was much easier to describe if you began withe the plunger resting above the bottom of the cylinder. Thus, we suggested to raise the plunger to the 2 cc mark before inserting the rubber stopper firmly in the can. Also air does leak out of the syringe slowly. If a large mass is being lifted, the leakage rate increases, so we suggest that you use a 50 g mass. After observing a few engine cycles, we should be able able to describe each  of the point a, b, c, and d of a cycle carefully, indicating which of the transitions between points were approximately adiabatic and which were isobaric. We observe changed in the volume of  the gas directly.

In the point a and point b, the flask put in the cold water, and from a to b, a mass set in the plunger to make the pressure become larger, and the volume of cylinder with trapped air became small. In the point c, the flash put in the hot water, the pressure became larger than point b, and the volume if cylinder with trapped air was larger than point a. In the point d, we took out the mass, the pressure returned the original pressure, and the the volume of cylinder with trapped air was lager than point c.

This picture showed the graph of the activity.

A Theoretical Analysis of A Heat Engine Cycle

A cycle made up of changed in volume made under constant pressure and changed in pressure made under constant volume.The gas has an initial pressure of 1.02*10^5 N/m^2, and an initial volume of 0.08 m^3. At first part, the hot water transfer just enough heat energy to the gas so that it expanded at constant pressure and did work on its surroundings until it had reached a volume of 0.1 m^3. Then, the gas was placed in the cold reservoir again and was cooled at a constant volume of 0.1 m^3, and the gas transfer heat energy to the ice water until its pressure decreased to 0.79*10^5 N/m^2. Next, we removed the collar and let gas cool further. At the same time, we kept the gas at a lower constant pressure while its volume was reduced the original. Finally, we made the pressure on the gas to rise to its original and returned the first part.

This picture showed the graph of the who activity and evaluate the change in internal energy for the whole parts of the cycle.

Isothermal and adiabatic processes for anideal gas

This experiment was the fire syringe. We put a little cotton into the inside of cylinder and pressed the plunger quickly. We found fire. At this activity, we should calculate the final temperature in the cylinder. Before approximating the final temperature of air in the syringe, we should knew the initial length if air column, final length of air column, inner radius of the tube, initial volume, finial volume, and initial temperature.

We used the calipers to measure the inner radius of the tube. The initial temperature is room temperature.

This picture showed all quantities that we need measure and calculate. 

Gas Law

The experiment showed that a can within a full of water was heated. After several minutes during the water boiling...

The water jumped to the can, and can condensed .The water was room temperature about 20 degree C before heating. During the water boiling, the water arrived at 100 degree C, so the inside of the can and outside of the can had temperature difference.According to an ideal gas law formula, P*V=n*R*T,the can inside became higher, so the pressure of inside can is also became higher. During the pressure of inside can extra high, the water would jump to the can. At this time, the pressure of outside was higher than pressure of inside the can, so the can would condense.

This experiment showed how the temperature affected the volume occupied by a trapped gas maintained at a constant pressure. In this experiment,we should have three different temperature water which were hot water,cold water,and room temperature water. To prevent spills, put the flask in the mug on the tray, the tubing in the rubber stopper hole, and the thermometer in the mug outside the flask. When we put the flask into the water with room temperature,the plunger did not remove. Since we would be cold water with the ice to reduce the volume of the trapped air, pull the plunger out. When we brought the flask back to the water with room temperature, the plunger return the original positive. When we put the flask to the hot water, the plunger reduce the original positive. When we brought the flask back the water with room temperature, the plunger came back to the original positive again.

This Picture showed the data and graph between the temperature and volume.

This picture showed that the relationship between the volume and temperature, the relationship between the pressure and temperature, the relationship between the pressure and volume, and the relationship with pressure,volume,and temperature. The Idea Gas Law is defined as one in which all collisions between atoms or molecules are perfectly eleastic and in which there are no inter-molecular attractive forces. One can visualize it as a collection of perfectly hard spheres which collide but which otherwise do not interact with each other. In a gas, all the internal energy is in the form of kinetic energy and an change in the     internal energy is accompanied by change in temperature.

                           

The first picture showed when the pressure of inside was decrease, the balloon became large. The second picture showed when the pressure of inside was increase, the marshmallow became small.They followed the Idea Gas Law.

This experiment showed a cylinder with a low- friction movable plunger to small flask, and there was a flask in hot water. 

When we held the plunger to keep the gas constant,the gas should keep hot. After a minute, we release the plunger and let it move freely, we know that the plunger jumped out at the end of lab.

Linear Thermal Expansion, Fusion for Ice, Vaporizaton for Water, and Gas Pressure

The first lab was Linear Thermal Expansion. We have a metal rod that was clamped on one end. There was one meter between the rod and the point of measurement. We would blow steam through the rod until the temperature of the rod matches the temperature of the steam. A rotary motion sensor would be used to measure how the rod moves as it is heated. The first and second pictures showed how to do the lab. The third picture showed the lab of the two graphs between temperature and time and the angle vs. time. From the graphs, we knowed that the temperature is increase and the angle is decrease. The forth picture showed how to calculated the angle when the rod was 1.5cm. The next lab was Fusion for Ice and Vaporization for Water. We used the water which mixed with ice would leave the coil uncovered. There were many water and ice mixture would take a long time to heat up. The fifth picture showed the lab. The sixth picture showed the graph between the time and heat. In the graph,the temperature was from -5 degree C to boiling, so in this lab, we could calculate the fusion for ice and vaporizaton for water. The seventh picture would show how to calculate the vaporizationn and fusion. The third lab was Measuring Gas Pressure with a Manometer. A manometer is an U-tube. The air close to the surface of the earth exerts force on each until of area it encounters. This is atmospheric pressure, which is often denoted the pressure of ATM. The columns of water on each side of the manometer experience this atmospheric pressure. If one column due the weight of the liquid that is above the level of the water in the lower column. It is a manometer for measuring. For this lab, we would construct a manometer with 2 translucent soda straws, 8cm, and 1 length of Tygon tubing 10cm. Put some water in the botttom of the manometer tube. Try blowing into one end, first very lightly and then somewhat more strongly.  The formula of pressure is P = F/A; F is force, A is area, and force equal weight, mg; m is mass and equal density multiply volume; pressure equals mass multiply volume, multiply gravity, and divide area, so the pressure equal mass multiply height, and multiply gravity, P = p*g*h.