Unit 8 day 2 (Power)

Power is work over time. The picture I have was as the weight room at TCU. Lifting weight is an example of power. You are able to measure power when lifting weights. It requires work to lift up the often large amount of weight, and it can also be timed. By finding the work and time, you can find power. Power is found all around us. Whenever we lift something for a certain amount of time, we can find power. In class, we used the example of running up the stairs, by calculating the work of a person, and timing them up the stairs, we are able to find the power they generate.

Unit 8

Unit 8 taught us about energy and work. One of the things we learned about was the conservation of energy. The system of pendulums above is a good way to view the conservation of energy. When you drop one pendulum, it makes contact with the other balls in the system. The energy from the dropped pendulum is transfered through the other pendulum, and finally enters the last pendulum on the other side. The energy causes the pendulum on the other side to swing up and come back down, causing this cycle to go on and on. Ideally, the system should work forever, but in our unideal world, the energy is sometimes lost. This also follows the work energy theorem. This basically states that energy in equals energy out, meaning that the energy that passes through the system should be equal to the energy returning in the other direction.

Picture - http://www.newgeology.us/presentation6.html

Today we did the egg drop experiment. The goal of this was to build a device to help a raw egg survive a 3  story fall. In order to do this, we needed to use our knowledge of collisions and momentum. The picture is of my groups system. We used a lot of padding and a box to attempt to cushion the fall. Unfortunately, it was unsuccessful. We went for a lot of padding and protection around the egg. The principle sounded good before hand, but ended up not working. The groups that were successful used devices that collapsed or broke, absorbing force away from the egg. Looking back at our device, I think the problem may have been the box. The box created a rigid outer shell, allowing nothing to bend or change shape. Had we not used the box, our bags of cushions would have flattened out on impact, potentially saving our egg. Overall, this lab showed me a lot more about collisions and the importance of time of contact on the surface it is hitting.

unit 7 day 2

On the second day of unit 7, we learned more about collisions and momentum. At the start of the day, we observed a car crash by the pool. This fit in perfectly because it was quite a collision. The picture I have is of my cousins car. He crashed it on a rock. The reason the car is so banged up is because the car came to a very sudden stop. If the car was able to come to a more gradual stop, the damage wouldn't have been so bad. Had he hit something like a pile of dirt, or a mound of hay, the impact time would have been increased, causing the car to slow down slower. As we work on the egg drop, we need to take into account the physics behind a crash. The purpose will be to increase the time of contact enough to prevent the egg from looking like my cousins car.

Unit 7

Unit 7 introduced us to momentum, impulse, and collision. This unit has very direct relations to my sport of football. The picture I have is of my friend Luke. I used it because it shows examples of a tackle. A tackle is a version of collision. On the football field, the collisions are not as uniformed or as perfect as our lab in class, but they occur constantly. As a defensive player approaches an opponent to make a tackle, he commonly has a greater momentum on his side. The velocity of a defensive player is usually greater because we don't have to do much dodging or turning, our goal is to go toward the guy with the ball. The best hits experience a larger impulse, the more momentum you transfer into your opponent, the better chance you have of trowing him off balance and to the ground. Overall, football demonstrates the factors of physics we learned in unit 7.

Semester review

This semester has covered a lot of ground in a few short weeks. From pendulum motion to balanced and unbalanced forces. The picture I chose is of my little sister playing volleyball. Volleyball can provide examples of the better part of the curriculum we covered in this semester. First off, the ball demonstrates the  different factors of movement. Distance, time, velocity, and acceleration can all be seen in volleyball. As the ball is hit, it accelerates forward, it then travels at a fairly constant velocity until it is hit by an opposing player. It also travels a certain distance in a certain amount of time. The ball is also a projectile, and demonstrates 2d kinematics. Finally, it demonstrates balanced and unbalanced forces. When it is hit, it is unbalanced. These are only a few small examples of how volleyball covers most of what we learned in this semester.

Unit 6

 

Unit 6 taught us about unbalanced forces. In the video the person is shooting an arrow. This demonstrates an unbalanced force. The bow applies force that causes the arrow to accelerate forward. Because the arrow accelerates, it is not balanced or doesn't experience equilibrium. Once airborne, the arrow is only under one force, the force of gravity. Since it is only experiencing one force, it is considered unbalance, because a balanced object is experiencing at least 2 forces. Overall, Unit 6 has been a big leap forward, it is different with a new equation, f=ma.