CTF Photo Project

The light hanging from the ceiling is experiencing two forces. The forces are gravity and tension. Gravity is pulling the light downward with 9.8 m/s^2. Without tension the light would fall to the ground and crash. However, the tension force of the rope is acting on the light with the same quantity force as the force of gravity has.

The shiny coating on the hockey stick is a sticky substance that helps you grip the hockey stick better. Many sticks have this in order for players to not lose grip while playing. The coefficient of friction on the stick is now greater than if it were to not have the sticky coating. This is similar to football gloves. With a greater coefficient of friction, it is easier to catch a ball rather than using bare hands.

The picture of the dumbbells relates to Newton's law of inertia. The law of inertia states that objects at rest want to stay at rest and objects in motion want to stay in motion. In this picture there is a 35 pound dumbbell and a 12 pound dumbbell. Also, with inertia, objects with greater mass tend to have more inertia because they are harder to move. Because of inertia, the 35 pound dumbbell will be much harder to move than the 12 pound dumbbell.

The punching bag, although not in motion in the picture, relates to momentum. Momentum is how difficult it is to stop an object. It is easier to move the punching bag when it is still rather then when it is swinging towards you. The reason is because it has a greater momentum. When it is still, the only factor acting on the bag is mass, the velocity is 0m/s. However, when it is coming towards you the velocity is increased while the mass stays the same. Because momentum is increased the bag is more difficult to stop.

My last picture is of a hockey puck on a sliding board. A sliding board is a tool hockey players use to at home to have the feel of ice. This relates to physics because the coefficient of friction is very low making it slippery. In order to have the same feel you need a surface that also has a very low coefficient of friction. Concrete is not a very good substitute since its coefficient of friction is much larger than ice. The sliding board is a good alternative to ice and allows many hockey players to practice at home as if they are on ice.

Owen Evans Bottle Rocket. Mr. Yav 2nd period

Materials used

Two 2 liter soda bottles: $4.98

Tennis ball: $0.83

Foam that came with my hockey helmet: The helmet cost $200

Cardboard box for wings: $1.77

Duct Tape: $3.09

Box cutter: $45.90

1 Garbage bag: $0.07

Section 1: Procedures

When we got the soda bottles, the first thing we had to do was drink the soda to empty them. However, two 2 liter bottles of soda is a lot of soda, so we ended up dumping most of it out. After we dumped it out we cut one of them in half and attached it to the other end of the bottle. After, Matt started making the parachute, and I worked on attaching the wings to the rocket. First, I started by cutting the cardboard into 3 triangular pieces. Then, I used the duct tape to tape the new wings to connect the uncut soda bottle to the cut soda bottle. After it was all taped up I realized that we would not have a part of the rocket to detach, so I took the tape off and taped them again to the uncut bottle so the cut part could eventually detach from the rocket. We then got a tennis ball and cut it open enough to where an egg would fit inside it. We then taped the new parachute to the tennis ball and tested it outside. It worked well so we rolled it up and put it away for later. However, the next time we took the parachute out, the tape was stuck to it and it ripped. So Matt made a new parachute, and we decided to not use tape and put the strings in the bottle and keep it in by closing the cap. We then got a cone that we would stuff the parachute into. When the launch day came. We stuffed the detached part of the rocket with the foam and the tennis ball which carried the egg and taped it shut. Finally, we stuffed the parachute in the cone, placed it on top of the rocket, and put it in the launch pad.

Section 3: Results

Because we did not attach the cone to the rocket, our parachute easily deployed. However, our rocket did not go very high compared to other groups. One factor that could play into our rocket not going very high is how there were many unattached parts which made the rocket not as aerodynamic as some other groups. Also, our rocket was not very long which also effected the aerodynamics. The upside to our rocket, is that our egg did not break because of our successful parachute deployment, and gravity would not accelerate the rocket as much as the groups whose rocket went over 100 feet.

Section 4: Conclusion

As I said in the previous section, our rocket could have been much better if it was more aerodynamic and longer. We could have added another bottle to make it longer which I saw many groups do. Also we could have found a better way to make our parachute detach. Many groups put the parachute into the extra bottle they added. We obviously could not do this because we did not have another bottle.

Here are some pictures from our launch:

Calculations: