Week 7

Last week, I see the data that we collected to calculate the height of the peak of the potato's launch. My calculations can be found in my previous post. Also that week, Audie and I attained all the materials for the wind tunnel and began working on the project. We will continue the wind tunnel next week.

Accelor the Potato Accelerator

Audie, Brandon, Dustin, and I launched a potato with the potato accelerator and recorded the data from the launch, which is as follows:

Total distance: 535'
Total time: 7.13s
Angle of elevation: 40 degrees
Observed height: 5'6"

We used two different methods to calculate the approximate height of the potato at its peak, then compared the two to determine whether the theoretical equation 1/2gt^2 (one half times the acceleration due to gravity times the time from peak to impact squared) was accurate.

Using the equation, we plugged in the acceleration due to gravity (9.81 m/s^2) and the time from peak to impact (3.565s), which was found by dividing the total time by two. Our equation then looked like this: 1/2(9.81)(3.565^2). After solving the equation, we found the height to be approximately 62.339m or 204.524'.

Our second method was to use trigonometry to find the approximate height. For this method, we had to find the distance from launching point to peak, and the angle of elevation from the observer's eye level to the peak point. We took the total distance and divided by two to get the distance from launch to peak (267.5'), and measured the angle of elevation to be 40 degrees. We then determined that, since the height, x, was the opposite side of an imaginary triangle from the angle of elevation and the distance from launch to peak was the adjacent side, we should use the trig function tangent (opposite/adjacent). Our equation now looked like this: tan(40)=x/267.5. Using algebra, I rearranged the equation to read: x=267.5tan(40). However, in order to account for the lost height due to the observer's eye level's distance from ground level, we had to modify the equation again to read: x=267.5tan(40) + 5.5. After some calculation, I found the approximate height to be 229.959'.

Based on these two calculations (204.524' compared to 229.959'), we determined that the theoretical equation was indeed reliable.

Week 6

This week, Audie and I created an inclinometer by attaching a protractor to a tube (used as an eyepiece) and attaching a string with a bolt as a weight to the protractor. We used this to mark the angle of elevation from my eye level to the peak of the potato's peak when launching from the potato accelerator. We also recorded the total time, distance, and initial angle of launch for multiple trials. We plan to use this data next week to theoretically calculate the height of the peak via trigonometry and our 1/2(g)t2 method to compare the two. Also this week, we researched plans and materials to begin our next project: the wind tunnel.

Week 5

During this week, Audie and I researched how to determine the height of an object dropped if you know the time it took to reach the ground and gravitational acceleration. We used the equation 1/2(g)t2 --*t squared*--. We took the total time from the time of the potato accelerator's launch to the potato's impact (4.34 s) and divided by 2 to get the time from the projectile's peak to its impact (2.17), thus giving us the t variable for the equation. The g variable is the acceleration due to gravity, which is approximately 9.81 m/s2 --*s squared*--. When we plugged this data into the equation, we came up with an approximated 23.097 m for the height of the peak of the projectile's motion.

Week 4

This last week of physics class, Audie and I decided to shift our focus from our hoverboard design to some motion analysis. We recorded a video of projectile motion by using a device to catapult a ball of play-doh into some plastic figurines. We used the Video Physics program on my iPad to analyze the x and y velocities and accelerations of the projectile's motion. I will include the video, graphs, and data in next week's post.

Week 3

After having the idea to create an even smaller mini disc for the hoverboard, we changed our minds once again. After standing on each of the two existing discs without the board, we concluded that, together, the two had enough lift to hold the weight of a rider. So, we decided that rather than spending the time and materials required to create another disc, we could instead turn the board and attach the two discs to either side of the middle section of the board. Once attached, the shop-vacs would rest on each end of the board itself (giving room for the rider's feet) and the rider would place one foot on the middle of each disc. Our hoverboard, with this new design, was a success.

Motion Analysis Video

I used Vernier Software & Technology's Video Physics program to analyze the velocity of a remote-controlled car. The car (during the video) has no acceleration since it has a constant velocity.

The program uses points in the car's motion to determine how far it travels in a set amount of time. The program then created a series of graphs, one of which was an accurate Distance Vs. Time graph.



I divided the change in the distance (y-axis) by the change in time (x-axis) at the one second interval to determine that the car's velocity was .334 meters per second to the right.