Rocket Lab

We started construction and test launches of our water bottle rockets today. My partner and i have so far chosen to add 4 fins each in the shape of a right triangle, and a parachute made of a trash bag and string. To our disappointment, after adding the 4 fins and the parachute, we wrapped the parachute a little to tightly on our first launch and it did not open when it was in the air causing our rocket to fly towards the ground and break 3 of the 4 fins off that sadly resulted in a launch time of a little over two seconds. After removing the fourth fin, we tried to wrap the parachute a little looser and launched it again. This time the parachute opened and resulted in a launch time of a little over 4 seconds. Although I am disappointed in our current results, we're slowly making progress and I hope to get a launch time of around 10 seconds tomorrow.

Unit 8 Part 2

In the second part of Unit 8, we learned more about the different types of energy and also learned about power. Power is the rate at which work is done and is measured in watts. We also used graphs to represent the distribution of total energy. In the first picture represented by my first graph, you can see that my friend jumping over my other friend has all of his energy in potential energy because he's at his maximum height and at that moment has a horizontal velocity of 0 m/s. in the second picture represented by the second graph, you can see that as hes is about to hit the ground which is a height of 0 meters, his potential energy is 0 because it has all become kinetic energy.

Unit 8 Part 1

For unit 8 today, we learned about different types of energy which are potential energy of gravity, potential energy of spring, kinetic energy, and work. Potential energy is the energy that a stationary object has relative to its height, mass, etc. and uses the formula "mgh." Potential energy of spring has the equation of "1/2 spring constant * d^2." Kinetic energy is energy of motion and uses the formula "1/2 m * v^2." All energy is conserved, therefore if an object at rest at a certain height has "x" joules of potential energy, when the object is about to hit the ground after falling from that height will have "x" joules of kinetic energy. The two pictures below represent the object at rest with "x" joules of potential energy and the same amount of kinetic energy as it reaches 0 meters.

Egg Drop Lab

For our egg drop capsule design, we used a bag filled with slightly crumpled paper, the egg was surrounded with a soft nylon foam like material. The nylon foam was used to cushion the egg in the case that it fell over after hitting the ground and was placed inside of our bag filled with crumpled paper. The crumpled paper was used to create a cushion of air that could still withstand the fall of the smaller inner capsule with the egg and foam which increased the contact time for when the bag hit the ground. We tried to make our capsule have a low mass so it would decrease the force that it took our capsule to stop when it brutally slammed into the ground. We also used rocks at the bottom of our capsule to attempt to stabilize our capsule during the fall. Here is a diagram i made trying to illustrate how our device worked.

Unit 7 Part 2

Continuing to learn about momentum, we went more in depth about impulse which is the change in momentum and can be represented by either the variable "j" or delta p. Having all of these values to keep track of has been extremely confusing for me and i always get a lot of them confused, especially because momentum and impulse are represented by variables that aren't the same as the first letter of the word such as v for velocity or d for distance. Since impulse is just the change in momentum, it was hard to grasp at first that in two different situations with constant variables except for contact time, the impulse will always remain the same, but the amount of average force per unit of time can differ varying the result oh say crashing into a wall with a contact time of .001 seconds and a giant pillow with a contact time of 3 seconds. We demonstrated this today by doing a water balloon toss and trying to move with the motion of the balloon being thrown to try and increase the contact time as much as possible and therefore decreasing the average force applied per second.

Unit 7 Part 1

Unit 7 so far has been about momentum and collisions. The variable "p" represents the value for momentum which has the unit of mass*velocity or kg m/s. The way that this relates to collisions is that momentum is conserved. When two objects collide, the amount of momentum at the beginning and end of the collision remains exactly the same. The way we tested this was using our air track to collect data of different scenarios of collisions and recorded the velocities, used that and the mass to find the momentum, and checked to see that the momentum was conserved supporting the "law of conservation of momentum."

Semester 1 Summary

So far, this course has honestly been tiring and at some times intense while at the same time being very intriguing. So much information has been packed into 3 long weeks that have felt like months. Generally speaking, we've only learned the basics of kinematics and forces, but 3 weeks ago I definitely wouldn't have been able to tell you how high a cliff is based on how long it takes to fall down, finding a distance based on the angle of trajectory, or even the now seemingly simple difference between velocity and speed. Although things were challenging quite often, it always kept me engaged and i can't remember a time where I wasn't either paying full attention or working on something. Besides the obvious challenges such as "I don't understand what the question is saying" and "We weren't learning this when I left to go to the bathroom 2 minutes ago," I can honestly say that I didn't have any problems whatsoever for these past 3 weeks. Overall, I have had a great time so far and anxiously look forward to the second semester.