Helicopter Overview

Key Ideas:

Nov. 28: “I’ve drawn up some FBD/VAD’s for how a helicopter moves, showing how the pilot has to tilt the rotors and increase the power to sustain forward flight.”

Nov. 29: “When the rotors are tilted, some of the power (lets say 10%) is going in a forward direction, while the rest (90%) is keeping the helicopter aloft. This means the pilot has to increase the power to have the vertical force be the same as when the rotors remained level.”

Dec. 1: “I will assume the maximum lift force is equal to twice the lift force required to hover. So, that force would be 63,000N. 31,500N are required to keep the helicopter aloft, while the rest of the force can be used to propel the helicopter forward. So, that means that the helicopter could tilt its rotors 60º before any loss in altitude was experienced.”

FBD reference:

 

Abstract: Helicopters seem to be mysterious things. My goal was to explain why helicopters must tilt their rotors and increase the power to go forward. I did this by drawing FBD’s and using trigonometry. Take a look at my work,

 

-B.

 

Worlds Deepest Trashcan Overview

Worlds Deepest Trashcan Summary

Key ideas:

Nov. 13: “We can calculate the theoretical depth of the trashcan using the Acceleration of gravity (10m/s^2) and the duration of the sound played in the video.”

Nov. 14: “I’ve graphed a simple Exel graph showing the velocity of the object. I’ve also timed the sound in the video (5 seconds).” See “Reference 1″ for the graph

Nov. 17: “Here’s the formula I’ve created for finding the theoretical distance a small steel sphere would fall with no air resistance:

D = (1/2)(5s)(50m/s)

D=125m”

Nov. 20: “We’ve found that, if the object dropped in the worlds deepest trashcan was a ball with no air resistance, then the worlds deepest trashcan is 125 meters down. But, sadly, nothing has a drag coefficient of zero.”

Nov. 28: “I filmed the video for finding the terminal velocity of a paper wad and a plastic cup today.”

Nov. 30: “I analyzed my WDT video using tracker today.” See Reference 2 & 3 for screenshots of the data analysis.

Dec. 1: “The terminal velocity of the paper cup is about -20m/s. So now, we can edit my original formula to fit this paper wad. The formula would now read:

D = (1/2)(5s)(20m/s)

D=50m”

Conclusion: So, the theoretical depth of the world’s deepest trashcan is between 50m to 125m.

Abstract: This Capstone is all based around a video posted by “Thefuntheory.com”. The video shows a trashcan that, when trash is placed in, plays a cartoon like sound of an object falling a great distance. Using information I know about physics, I was able to calculate the theoretical distance that the object would have fallen if the trashcan really was “The Worlds Deepest Trashcan”.

WDT & Helicopters (Not at the same time)

From my earlier post, I found the worlds deepest trashcan distance using this formula:

D = (1/2)(5s)(50m/s)

D=125m

The formula, though, only works for a solid metal streamlined body. I’ve measured the terminal velocity of a cup & paper wad, and here’s what I’ve found:

The terminal velocity of the paper cup is about -20m/s. So now, we can edit my original formula to fit this paper wad. The formula would now read:

D = (1/2)(5s)(20m/s)

D=50m

So, the range of the world’s deepest trashcan is between 50m to 125m, depending on the object thrown in it. This trashcan is not only the worlds deepest, but the worlds smartest (With the ability to change its depth depending on the object thrown in).

 

Now moving on the helicopters.

The first picture (FBD’s not drawn to scale) shows a FBD using the Drag Force formula given. When the helicopter is at its maximum velocity, the Fnet must be equal because the body is not accelerating. With the Drag formula given to me (Fd = .4v^2), the total force produced by the helicopter was barely bigger than the force required to hover. This seemed odd to me, because I was told to assume the maximum force created by the rotors was double the force produced required to hover. The second picture shows what I think is a more accurate FBD for the Maximum velocity. I was told to assume the maximum lift force is equal to twice the lift force required to hover. So, that force would be 63,000N. 31,500N are required to keep the helicopter aloft, while the rest of the force can be used to propel the helicopter forward. So, that means that the helicopter could tilt its rotors 60º before any loss in altitude was experienced.