It's not the Vf=Vi+a(t) that kills you, it's the F=m(ΔV/ΔT).

Sunday, October 30, 2011

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.

Sunday, October 16, 2011

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.

Wednesday, October 5, 2011

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.

YouTube Video

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.

Monday, October 3, 2011

Week 2

Last week, Audie and I got our hoverboard totally assembled and ready for a test run. When we fired it up, it worked beautifully. However, when we attempted to ride it, we discovered that there were three main issues we needed to address:
1) The entire board would vibrate violently.
2) The plywood that we stood on would bend under the weight of a person.
3) Because the plywood would bend, the board would no longer slide.

To solve this, we decided to disassemble the hoverboard and replace the original 1/2" thick plywood base with a 5/8" thick one.

When we reassembled the improved version, we observed that while the vibration had ceased, the board still bent, just not as much.

So, we made plans to build another mini hoverdisc, this time with a 1.25' diameter. We hypothesized that this mini disc, when mounted between the other two (underneath the rider) would both keep the board from bend and put less pressure on the other two discs, making the board slide better.