Dipole moment & Flux

Here we show electric fields and there effects on a positive and negative charge, which is they go in opposite directions. By treating the particles as if there was a rod between them, then there would be a negative torque applied to the rod. The torque can be found by knowing the quantity of p and the angler the center of the rod makes with the horizontal

 

Here we put a conductive metal cylinder on top of a device that supplies electrons. We predicted that the excess electrons would cause the foil pieces connected to the string to move away, both inward and outward, from the cylinder. What really happened was only the outer foil pieces moved away from the cylinder. This is due to the simple principle that excess electrons will get as far away from one another. We also discovered that the electric field inside a conductor is zero.

Here we explore the concept of Flux, which is the difference between the electric fields going inside and outside of a surface.

Above are the solutions to a questions in regards to flux.

Electric Field, Field Hockey

Just like there are certain properties of a gravity field, we correlated those to an electric field.

Here we solved a problem of determining an electric field of an object composed of several different charges throughout

 The above three pictures were from a program to help familiarize ourselves with electric forces and lines. By playing with the distances between, as well as the charge, of the particles, we were able to see the effect of the force and field.

Here we answered several questions regarding electric fields.

By recording the electric field between uniform distances and using a graph that increase by that same uniform distance, we were easily able to determine the fields present at points on the graph

In the above screenshots, I played field hockey and guided a charged particle into a goal through the use of positive and negative charges.

Electrial force, Coulomb's Law

 Here we rubbed a balloon with a piece of fur. The balloon sticks due to the electrons it took from the fur. These extra electrons create a force towards the glass that is equal but opposite to the normal force.

 After putting pieces of tape onto the table, we took them off and placed them towards another. They repelled one another.

  Just like mass has forces between them, charges have forces between them. That is what we are illustrating with the above equations. A key difference is that the force can be negative or positive for charges, where as it is only positive for gravity. The 2nd equation from the top is called Coulomb's Law, and is used to measure the electrical force between two point charges

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In the above two pictures we made a graph measuring force and used relationships to solver for the charge

 Here we had two seperate charges, q1 and q2, separated by a distance r. We used Coulomb's Law to solver for the force between them.

 

Just like above, we used Coulomb's Law to solve a problem, but did so in the x and y planes.

 

Here we use a device that transports electrons to the top, thus transporting its' excess electrons out of the top

  

Here electrons are shooting to the blades of the propellers. The propeller are moving due to the combined velocity of the electrons.

 

Here the excess electrons get transported to the hair strands. Now that the strands have the same negative charge, the repel from each other as seen in the picture.

Thermodynamics: Engines and Entropy

 Here some green liquid was poured into a cup of water. This was to demonstrate the concept of entropy. Entropy is the measure of disorder in the system. In another situation, pennies were dumped onto a table to demonstrate entropy increase.

 Here an engine was used to move a propeller. The device had ice placed on top and hot water at bottom. It then used the difference between the two to power the engine.

 Here we graphed an isochoric and isothermal process on a entropy vs. temperature graph. We also found the efficiency of a device.

 Here we converted units between two systems. We went from a unit used in the United States, and converted it to metric units. We started with 1 BTU, went to calories, then Joules.

Here we worked on an example involving items freezing in a freezer. We first found the max performance, the power, and then how long it would take for our item to freeze

Types of Thermodynamic Processes and 2nd Law of Thermodynamics

1. Candle

 Here we placed a candle in a flask, where it quickly went out. We also put a thin tube just over the flame when it was at the bottom, which allowed the flame to keep going. This was because the narrow tube provided an escape for the CO2, while the oxygen could feed down the outside of the tube.

2. Types of Processes

 In the two pictures above, we drew several graphs of the different thermodynamic processes. These included isobaric (constant pressure), adiabatic (no Q transfer), isochoric (constant volume), and isothermal (constant temperature)

3. Isothermal Process

 This device helped us witness an isothermal process. Turning the handle at the top controls the piston in the cylinder. Using this, you can perform work on the gas inside. Done slowly enough, you can keep the temperature constant.

 

Here we solved the work required to get the piston from one position to another in the above device

4. Problem Solving

 This is the solution to a problem involving a water tank. The work to pump water into the tank involved gravitational potential energy.

Here we witnessed a heat engine, which converted heat into mechanical energy.

First Law of T-D, Kinetic Energy, and Cylinder Spark

Today we worked with the concepts of Kinetic Energy and the First Law of Thermodynamics.

1. First Law of Thermodynamics

In the above picture, we were conveying the relationship between the work someone does, the heat they acquire, and the energy they use.
                   

 Here we expressed work in terms of the pressure and volume change, instead of force and distance that force moves the object.

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Here we demonstrated the equation "energy change equals the heat absorbed minus the work performed". The bar is heated, so it absorbs heat. Also it expands in size, which equates to positive work. The difference between these two is the internal energy change of the object, which is positive in this case.

2. Kinetic Energy

Above we used the relationship between kinetic energy and temperature to rewrite pressure in terms of kinetic energy, number of molecules, and volume.

3. Cylinder Spark

Here we used the ideal gas law, pv = nrt to figure out if a material placed inside a cylinder would ignite. We could ignore the moles of air and R, since those are the same in the initial and final states of the cylinder. By measuring the initial and final volume as well as the initial temperature,we predicted that the temperature would be enough to cause ignition, which it did.

Ideal Gas Law: Crushed Can, Straw Pressure, Graphs, Balloons/Marsh mellows, and Diving Bells and Balloons

Ideal Gas Law: Throughout today's experiments we worked with the Ideal Gas Law. We did this by working with the variables within, volume, pressure, moles of gas, and temperature.

1. Crushed Can

 Here we filled a can with warm water, and placed it upside down at room temperature water. The can collapsed due to pressure difference.

2. Straw Pressure

Here we blew on water within a straw to get it to move some distance. We then worked with the equation Pressure = (force/area). Noting that the force was equal to the weight of water, and that the mass was equal to water density times gravity, we rewrote the pressure equation in terms of density, height, and gravity.

3. Ideal Gas Law quantity graphs

Here we worked with three quantities from the idea gas law: pressure, temperature, and volume. According to the equation PV = nRT, all the values should have a linear relationship, which is what we drew with the solid line on the graphs in the above picture. However, for volume vs. pressure, it was a curve, as opposed to a line. They have an inverse relation, since P ~ (1/V).

4. Balloons/Marsh mellows

 Here we placed a balloon and then marsh mellows inside a container and sucked the air out of it. We reduced the pressure, thus increasing the volume of the items. This is because the air inside them wants to expand to the rest of the space within the container, in line with the Ideal Gas Law. When we returned the container to the prior pressure, they were smaller then they were originally. This is because some of the air within the items had escaped them in the reduced pressure atmosphere

 5. Diving Bells and Balloons

 

 Above we did two seperate problems involving the idea gas law, as well as buoyant force. We used these equations to figure out the change of air height due to pressure difference, as well as the max payload mass of a balloon.