Particle in a Box

In the particle in a box active physics much was learned visually about the abstract world of modern physics. The two varying factors are the length and the mass. There are two wave functions that are simply psi and psi squared. Psi squared also actually equals the probability of the chance that particle is within a certain area.



The graphs also show a different value for the value of n which, the probability of finding the particle in that area is much higher as the values of n rise. As the length increases and decreases there are many changes that occur to these probabilities. The longest wavelength with a standing wave L is on that goes to twenty times ten to the negative fifteenth meters and the mass at the minimum must be 1.0 times the mass of a proton.

This is the energy of the ground state this can also be written as E = h^2/8mL this is the equation derived and given for an atom in ground state for a particle in a box. As the length of the box in this denoted as L increases then the value of the energy is decreased. It is inversely proportional to the ground state energy of an atom.


In this photo the value of the length of the standing waves has not been changed however the mass has been increased. Instead of being only the mass of one proton, the mass is now increased to five protons. This value makes the energy much lower. When the energy levels are higher the amount of energy is not nearly as high as any of the other energies as the mass is increased. Basically the higher the mass the lower the energy weirdly.

Active Physics Relativity

The active physics relativity gave a much more visual perspective of relativity. This included time dilation as well as length contraction. The field of simultaneity also applies which shows and proves that time is relative; depending on what frame of reference is given, each person has a different perspective on how fast something is traveling, the time it takes to reach that person and the contraction of the length given.



A time clock is given and it shows the time dilation when one is moving. If the value of gamma is higher, the time dilation is greater. This theory shows the effects of time travel that man has been forever struggling to do. This effect of time dilation has been proven in a way. Active physics is a great way to visually understand the effects of relativity.



The distance of the light travel is relative to how fast the movement of the frame is, however this only works at very high speeds and that any nonrelativistic speeds, this theory will not work. There are also many interesting things that happen at relativistic speeds such as the relativistic momentum and relativistic mass all depends on what frame on is in.


Relativity is basically just like a non relativistic depiction however whatever is the previous value of the time dilation and length contraction is just multiplied by gamma to find the change in time or length or even momentum. In the length contraction, the varying factor in the visual program is the length. When it shows that the length increases by a certain amount, then the time it takes for one light to get to the end increases giving the length a certain amount will be contracted.

Planck's Constant from an LED

In this experiment, the value of Planck's constant is to be measured using the wavelength of the different colors of the spectra. The theoretical value of Planck's constant is h = 6.626*10^-34 J s, but hopefully the actual value will be very close to that. There are several things that have been done in previous labs that will be used on this lab. The same setup as done with the color and spectra lab using 2 meter and 1 meter sticks to determine the wavelength of a given color. However, this time a different color light is given.


A diode is used in this laboratory which makes sure that the current does not flow in a seperate direction. There were four colors being tested and the voltage was given: red 1.87V, green 2.51V, Blue 2.62V, Yellow 1.89V. Using the equations Energy = charge of electron X voltage, and E= hc/lambda, E = -A/n^2, the wavelengths were calculated. Another measured distance was the distance from the light bulb to the color spectra. These were blue was twenty five centimeters, green 30 cm, red 37.5 cm, yellow 34 cm.


After many algebraic and geometric equations the values of planck's constant were fairly close to the calculated values. Values of 6.53 * 10^-34, 6.36 * 10^-34, and other values close to those values. However, like any other laboratory experiment there are possibilities of uncertainty. No matter how far one can measure something to, there will always be some value of uncertainty.



Human error in this lab is very high because it must be done with two people, making it harder to clarify what one sees. Of course, there is uncertainty in the other measurements as well such as the distance of the length from the LED to the diffraction grating.