Lab 15 Carlos Hernandez

Collisions in two dimensions

Name: Carlos Hernandez

Partners: Dhalia Tran, Ariel Tran

Date: 10-17-30

1. In this lab we wanted to see a collision where the objects did together and see if energy was conserved. 

2. I did not come the 2nd day of this lab as I injured my back. So all I did was was capture the video of the 2 marbles colliding and putting it into loggerpro, and tracing the path of the balls frame by frame. I understand it is my responsibility to finish the labs on another day and take full responsibility. Cheers. 

Lab 14(not named in lab book) Carlos H. Ballistic Pendulum

Ballistic Pendulum

Name: Carlos Hernandez

Lap Partners: Dhalia Tran, Ariel De Leon

Date: 10-12-16

1. In this lab we will find the velocity of a ball firing into a ball going up a theta.

2. In this lab we utilized a ball . A pendulum mechanism which when firing a ball into the block will go up an angle theta. the ball stays inside which will make it into a inelastic collision. A slow motion video will be posted below on how the mechanism works.

3. We did 3 trials of shooting the ball. Getting 3 thetas and using the average. The mass of the block was 84g and the ball was 8g both with a +-.1 in uncertainty

L up in the work is the length of the string, being 21 cm. When plugging in the data our V initial for the ball come out to be around 6m/s 

After this we decided to do the second of the lab for fun which is if the ball is shot from the table how far away will it land. we measured the height of the table, distance inside the table where the ball will be shooting from and with simple kinematics ( Y direction to see when it hits the floor then use the time to find the x distance) the distance away from the table would be 2.44m and the total distance traveled by the ball would be 2.7 m work will be posted below. 

In conclusion, in this lab we use  the conservation of momentum and the conservation of energy to find the velocity initial of the ball, and therefore use a few measurements to find the distance the ball would travel. This ballistic pendulum lab was great to show how momentum and energy are conserved. Cheers. 

Lab 13 Carlos H. (Magnetic Potential Energy Lab)

Magnetic Potential Energy 

Name: Carlos Hernandez

Lab Partners: Ariel De Leon, Dhalia Tran

Date: 10-10-16 & 10-12-16

1. In this lab we will be analyzing and looking at the conservation of energy with magnetic potential energy.

2. In this lab we utilized a track which blows air, a cart mounted on the track which with the air makes it have virtually no friction(negligible). a magnet at the end of the track, caliper, meter stick, books, to help balance the track to a level surface,  a strong arm to lift the track for the experiment, and a photo to measure angles. 

3. We raised the track like so at an angle theta, we used a phone to measure the angle theta and with a caliper measured the distance separated by the magnet. We raised the track and took data 8 different times , a photo with the data is placed below.

After collecting out data we then put graphed in logger pro the force of the magnets by the distance of separation, we then put a power fit on the graph to get a fitting function where A is multipled by r raised to B

This concluded the first day of the experiment, on the second day we now used a motion detector, measuring a distance from the motion detector to the cart and the cart to the end of the track to get our distance that needs to be subtracted from our distance measured by the motion detector. Our separation ended up being .3621 +- .1 (from the ruler) After this we made a collection of data with the cart slowly (constantly) moving towards the magnet and moving back. With this data we are able to calculate or Kinetic energy and Gravitational energy given from the previous part of the lab.

After inputting our U-mag and KE information into logger pro we managed to see what the total energy of the system was . Surprisingly the experiment went well and the data collected looked great. The total energy did not go up (which would be crazy!) and tried to remain constant. The slight decrease to my thought might be due to some slight friction on the cart nevertheless we see how conversation of energy remains through all forms of energy and try it out through a magnetic lab which is great. Cheers.

Lab 12 Carlos H. Conservation of Energy-Mass-Spring System

Conservation of Energy-Mass & Spring System

Name: Carlos Hernandez

Partners: Dhalia Tran, Ariel De Leon

Date: 10-5-2016

1. The essence of this lab is to look, analyze, and understand the energy in a vertically- oscillating mass-spring system where the mass of the spring is non-negligible( has to be taken into account). (the reason this lab has the text centered is because there is a glitch that doesn't let me write from left to right.)

In this lab the utensils that were used where; a spring, mass , motion detector, a paper to make the motion detector read the position better and Logger Pro. the information retrieved is the following , Mass of Spring = .065 kg, Mass Hanging On Spring = .45, Height in the Bottom = 1.23 m. 

After making out spring oscillate up in down in a smooth motion we managed to get this beautiful sinusoidal graph which is essential to help us get the spring constant which was k= 16

In this problem we needed to integrate the sum of all the Gravitational potential energy by getting a small piece of dm of the spring, and dh, and the integration was from a y from the bottom to dm. Another thing that was solved for was an expression for Kinetic Energy for the spring.The elastic potential energy equation that was used was .5*K*X. So the total energy for the system was 1. Gravitational of the handing mass and spring, 2. KE of the hanging mass and spring, 3. And Elastic Energy. The work for the calculated equations is below. 

All the equations for energy were input into logger pro and are below. 

The sum of all these energy throughout the entire position should remain relatively constant, I believe if there is much error it would be in measurements or calculations, I was pretty happy with the graph we got for the motion and feel like there isn't much more places where error could be at. In this lab we see and experiment with the Conservation of Energy extensively and feel like at first it was quite difficult to understand but looking back, was very helpful and makes perfect sense. Cheers  

Lab 11 Carlos H. Work-Kinetic Energy Theorem

Work-Kinetic Energy Theorem Activity 

By: Carlos Hernandez

Partners: Ariel De Leon

Date: 10-5-2016

1. For this lab we will see how kinetic energy is related to work, using a spring. 

2. 

The tools utilized in this lap where; a cart, track, spring, force detector, motion detector, and a small piece of cardboard to make it easier for the motion detector to read the position. The premise of the set of the cart shown above is to after balancing out the force detector, measure the position of the card and the force by the connection to the spring.

In the top part of the graph the force was graphed by the position we selected the part of the graph that would be most useful to us as the beginning and the ending part of the graph would make our calculations faulty(I'm not sure if that is a word). After excluding the outer parts we integrated graph which gives us the work done in that period. Below we inputted values and graphed kinetic energy. The kinetic energy we got was 1.942 J while the work done was 2.379 J. this means there is about a 29% error in between the values. We did feel this percentage was fairly high so we redid the experiment as there was an uncomfortable feeling for the high percentage. 

In this trial our work turned out to be 1.996 N while the Kinetic energy in the graph below was 1.659 which gives us a error between the values of  about 27%, the percentage was still high but we believe that there might have bee error by the sudden jolt on the cart when letting it go after stretching the string and such. And the end on the lab we still manage to see how the area under the graph for force by distance gives us the work done where we can see the kinetic energy of the system, cheers. 

Lab 9 Carlos Hernandez Centripetal Force

Centripetal Force With A Motor

Name: Carlos Hernandez

Lab Partners: Dhalia Tran, Ariel De Leon

Date: 10-3-2016

1. Our job for this lab is to understand and show the relationship between Angle Theta and The angular velocity (w).

2. So for this experiment we have a system that looks exactly like the above, the middle top part rotates causing the string to rotate as well . The angle and height little h are all dependent on the angular velocity, the first thing we do is find a few key measurements that we will need for this experiment. Here is a photo of what was measured as well as a photo of the system at work.

The photo to the right was edited to show the strings "motion" and a circle was put to show where the end of the string is traveling.

In the work from the picture above we solved for omega (w) using the diagram on top, a free body diagram and omega related equations. After having our equation from above and the data collected stated in the beginning , we were ready to place our data in excel. 

The Data was input including the 2 different ways of solving for omega(t),using the (2*pi)/time and the omega(h) using the equation solved for in the previous photo.  Once we had our two omegas, we plotted them vs each other homing to get something close to a slope of 1/1 which we did, thus proving that either way we can solve for omega. I was actually surprised by how great the plot came to be considering the various ways there could have been error in measurement.

The lab was a success and the equation derived worked like a charm and shows that we can solve for omega using theta and the height of different positions which is definitely very useful. The error was very minimal but most likely due to measurement error, or time keeping error.    

Lab 8 Carlos Hernandez

Demonstration--Centripetal Acceleration vs. Angular Frequency

By: Carlos Hernandez

Lab Partners: Dahlia Tran, Ariel De Leon

Date: September 28, 2016

1. We want to show and understand how Ac=(V^2)/R is related to w=V/R where Ac is Centripetal Acceleration and w is angular speed. Therefore we want to know and understand how the Centripetal force is m*R*w^2

2.  We all know and understand how The Force of an object is equal to the mass multiplied by the acceleration . Now we Know the Acceleration for Centripetal force is the equation stated above now we want to understand this, this lab will be done documenting data that the professor gets from the rotating table, there is a block attached to the center of the center by a string from this mechanism we will know the following information, mass of the block(we change it throughout the experiment), Radius in cm, Volts inputted to the system, Time in sec, and the Force gotten by the Force detector attached to the block and the string. The professor did this experiment several times like so; 4 times with the mass of 200g , the radius of those 4 times being, 19cm, 28.5 cm, 40 cm, and 54 cm. the volts for those for times was fixed at 6.1 , and of coarse the time and Force changed for each scenario, a photo with all this data will be below. After those 4 trials the mass stayed the same for the following next 3 trials as will as the radius at 54 cm but the volt input were changed to 6.6 , 7.0 and 7.7. after these 3 trials there was 1 trial done with the mass at 100g, radius 50cm, and volts 7.7, and one last trial with the mass at 50 g  radius 54.