2-12-2014 Periods of Oscillation Lab# 22

Purpose

The purpose of this lab was to calculate the period of a half circle that we cut out of Styrofoam cardboard.

First we had to calculate the I in order to to plug it into our parallel axes theorem that will get us our Icm. With the r of the circle measured we were able to solve for the period once the Icm was plugged into the angular momentum formula. Our calculated period was .636s.

 After calculations were finished we had to attach our semicircle to an apparatus that would measure our period through the sway of it. The period found on the graph was.6113sec.

So our percent error turned out to be 3.93%

25-11-2014 Mass Spring Oscillations Lab#21

Purpose

The purpose of this lab is to compare the spring constants and periods of multiple different springs.

In order for us to accomplish this lab in the short amount of time the class was split into two different groups. Then each side was assigned five different springs to test within groups of three or four people.

First everyone had to weigh the spring and right their mass on the board. Whosoever mass was the largest that was considered the constant while everyone else had to adjust their masses to compensate.












Then we had to use our own methods of getting the spring constant. We ended up measuring the distances with weight on the spring with a motion sensor. then graphed it and plugged in to the given formula. Our spring ended up being at period of .42 sec and 23.3N/m spring constant.

 

 With the recorded periods from the other groups we plotted the values.

20-11-2014 Conservation of Linear and Angular Momentum Lab #20

Purpose

The purpose of this lab is to find the angular momentum about a point that is external to a rolling ball.

In order to set up this lab you need the Model ME-9821 Rotational Accessory Kit and the ME-9279A Rotational Dynamics Apparatus. We as students were not able to actually preform the lab ourselves so Professor Wolf is the one that demonstrated it to the whole class.

However, before he used the kit we had to find the calculations ourselves. First being the velocity from launch. While we were calculating Professor Wolf used the graph to give us the angular acceleration which turned out to be 5.64rad/s^2.

Then we had to calculate the moment of inertia using the velocity and angular acceleration we found and were given. This is going to be used for the next part of the lab that was also preformed by Professor Wolf.

Then Professor Wolf ran another part of the experiment with the second set up. For this part the ball was launched at the same height but caught in a catcher that spun the disk at a certain angular velocity. He told us to figure out what the angular velocitythrough calculations while he did it experimentally. Our omega turned out to be 1.95 rad/s

This is the apparatus he used to find the omega.

On his graphs he came up with omega =1.775 rad/s.

18-11-2014 Angular Momentum Lab#19

Purpose

The purpose of this lab is to find how high a ruler can swing if released from a leveled height and released only to collided and stick to a piece of clay.

We have a ruler with a hole drilled through it and attached to a force sensor even though it is not what is collecting data. Then we have a large piece of clay with tape wrapped around it for extra sticking power and it is sitting on a rod that is leveled with the ruler. We collect the data by video recording the motion and doting it as it moves.

However, before we do the experiment we have to do or calculations of what our height will be which was 0.303m.

After calculations were done we collected our data by recording the video.

So with the collected table the highest height recorded was 0.2325 m. With our theoretical being 0.303 or percent error was -30%.

13-11-2014 Moment of Inertia of a Triangle Lab#18

Purpose

The purpose of this lab is to find the moment of inertia of a triangle when it rotates about its center of mass using the same air contraption we did in lab 16.

 

  Before we could find the inertia experimentally we had to figure out our moment of inertia through our own calculations.

The calculated inertia for short is 0.5998 kg*m^2 while the inertia for the long side is 0.002593 kg*m^2.

Then once that is done we were able to use the apparatus to actually measure what the inertia is compared to the calculated.The first one that was run was without the triangle with the average acceleration being 2.469rad/s^2

Then the next was the with the triangle but with the long side up with the acceleration at 2.017 rad/s^2.

Last was the triangle with the long side down with the acceleration at 2.34 rad/s^2.

With all of the accelerations calculated we could find the moment of inertia along with the percent error.

06-11-2014 Moment of Inertia Lab# 17

Procedure

For this lab we had to calculate the moment of Inertia of a wheel then we would determine the time it takes a cart to fall when the string is attached to the cart and wheel.

We had to measure the diameter of the big disk and the diameter of the axle as well. Which are on the bottom of the board. Since we did not know the official mass we had to calculate it. In the end it was 4.159kg. Then once done we had to calculate the moment of inertia with all the collected measurements. It turned out to be I= 0.0207 kg*m^2.

Once finished with that we had to calculate how long it would take for a cart to roll down a ramp. since we are not given velocity we had to figure it out with our own method. We chose to video record the wheel rotating on LoggerPro and dot the motion to get it.

Then we graphed those points and fit it to a linear fit and used the slope as our velocity.

 

With the velocity now known we calculated the time that the cart should take for it to
roll down the track. Which turned out to be 8.27seconds.

Then we tested our theory and actually timed the rolling cart. But our time turned out to be 10 seconds. Meaning that our percent error was 17.3%

16-10-2014 Angular Acceleration Lab #16

Procedure

Our goal is to gather data that will help us get the angular acceleration.

The way we will accomplish this is by using a complicated pulley system that looks like it can straight out of the 70's. This apparatus is attached to an air pump in order to create little to no friction between the disks.

Before we can start though we had to determine the radius of most of the disks along with some masses.

Once that is collected we had to follow a chart that told us to collect data with different sized disks.

The angular acceleration was gathered using the graphs collected with the LoggerPro and finding its linear fit. The slope of the line is our angular acceleration.
Our angular acceralations in order turned out to be:
1)1.085 rad/s^2

 2)1.528 rad/s^2

 3)1.973 rad/s^2

 4)2.330 rad/s^2

 5)5.895 rad/s^2

 6)1.069 rad/s^2