D-Day minus 2

It was a sunny day for takeoff, only a few clouds in the sky. We observed the other teams attempt to take off but were immediately shot down and burst into flames by there own power source. A sad sight to see...
Our balloons took flight yesterday at 1125 hrs. on Tuesday the 4th of June. We had a hang time of about 7 seconds. That was just with out hairdryer power source. We also experienced with a napalm accelerant that burned too hot for our balloon and the chimney we used to fill the balloons.
Overall if was fun testing our napalm and making balloons.

Hot Air Balloons

We have made hot air balloons in Physics. We made them out of tissue paper and rubber cement.

My fellow colleague Adam Furore and I been experimenting with alternate fuel sources to power our balloon. First I had the idea to make a simple napalm like substance out of powdered sugar and isopropyl alcohol. We tried mixing it with rubber cement and had a maximum burn time of 10 mins. with about 20 mL of the mix. Over the Weekend we made actual napalm out of polystyrene packing peanuts and regular gasoline. this napalm burned far longer and hotter than any of the other mixes thus far. When we burned our first test of the napalm on a sand pile it burned so hot, in fact, that we made a dirty glass by accident. To confirm this hypothesis, we did a second a second test burning about the same amount of napalm in a clean aluminum cup and all it produced was a thick layer of soot, leading us to the confirmation that we made a dirty glass.



The principal that make the balloons fly is Archimedes' Principal and Bernoulli's Principle. Hot air is less dense than cool air, so it rises.

Overall, it was a lot of fun making really flammable stuff and testing it in a scientific way.

Little Shop of Physics

I did the "Rubber Pencil" experiment. It was quite entertaining. A good way to pass time when you are board.

According to the site this is what happens.
"The monitor redraws the screen from top to bottom at a rate near 60 Hz. This means that it will act like a strobe light, and allow you to "stop" fast motion. But since it is drawn from top to bottom, it will stop the motion at different points! So it will look like the pencil has curved: the top will be stopped at one time, and the bottom at another time!"

This makes sense and I found that it also works not in front of the computer screen, just not quite as well but still entertaining none the less.

Tides and Gravity Labs

Critical Speed Lab
1) the earth needs to be traveling at 29,500m/s to successfully travels around the earth.
2) The earth will fly off tangent to the sun if the earth's speed is greater than critical speed
3) The earth will crash into the sun if its speed is less then critical speed
4) The planet closest to the sun will travel faster than the planet furthest away from the sun.
5) Venus's critical speed would be greater than Mars's.
6) A and C are connected and have the same speed.
7) The spaceship would be sucked into the neutron star because of its massive amouts of gravity.
8) Gravity holds the earth together.














Gravitational Force Lab
1) Point A has a greater gravitational effect on the moon because it closer to the moon.














2) Because the distance is shorter between the moon and the Earth.
3) Because the earth has a high tangential speed so it is falling around the sun.
4) r because gravitational attraction is directly related to teh distance between the two objects.
5) a Increase
b Increase
6) a Decrease
b Decrease
7) Point A

Tidal Force Lab
1) The Earth and the sun have the largest gravitational force.
2) The Earth and the moon have the largest tidal force.
3) For tidal effect, two objects located close together is more important than the strength of gravitational force.

Torque Project

Here is the powerpoint explaining our science project.

PowerPoint Presentation

Torque is defined as force multiplied by the distance from the fulcrum.

Finding Center of Gravity

Date: 12/19/07

Purpose: To find the center of gravity of a pencil

Equipment: Pencil, and Triangular prism to use as your fulcrum point


Procedure:

1. Step # 1 – Place the pencil on the fulcrum.
2. Step # 2 – Move the pencil about the fulcrum until it balances without you touching it.


Conclusion: When the pencil is balanced on the fulcrum, You have found its center of gravity.

Potential Energy Gizmo

Calculationg Gravitational Potential Energy
1. a) The potential energy of the ball on the ground is 0J.
b) The potential energy of the paper is .31J.
c) If the paper is raised, its PE increases. If the paper is lowered, its PE decreases.
d) Horizontial movement has no affect on the PE of the paper.
e) The PE of the paperclips at the 2m shelf is .78J. The PE of the clips doubles at the 4m shelf to 1.57J.
f) I would expect the PE of the paperclips to be cut in half when they are lowered from the 2m shelf to the 1m shelf. Its PE is .39J at the 1m shelf.

2. a) PE of Ball: 1.96J Paperclips: 0.78J Paper: 0.16J
b) The ball has the greatest mass. The wad of paper has the smallest mass. The larger the PE the larger the mass.
c) The GPE is equal to mass times acceleration due to gravity (9.8 m/s) The Balls GPE is (1.96)=m(9.8)(2)) --> m=0.1g; The mass of the paperclips is (.78)=m(9.8)(2)) --> m=0.04g; The mass of the wad of paper is (0.16)=m(9.8)(2) --> m=0.009g
d) The PE of the clips is 1.96J at the 5m shelf; The PE of the wad of paper at the 3m shelf is 0.24J.


1. Ball Placed at the 1m Shelf
a) PE= 0.98J
b) PE at 4m = 3.92J
c) the PE quadrupled

2. Paperclips on the 5m shelf.
a)PE=1.96
b)PE at 3m =1.18
c) there are no other forces other than gravity acting on the paperclips. It is nagative because you are going from a higher level to a lower level.

3. Paper on the 2m Shelf
a)PE=0.16
b)PE=0.16
c)Net change of the paper is Zero. No work is being done by non-gravitational forces.