Quarter 2, Blogpost #7 (Egg Drop)

Last Wednesday, just before Thanksgiving break, our class held our "egg drop". My partner was Kanoe Sakamoto and our assignment was to create a capsule that could contain an egg and protect it from being broken after being thrown 3 stories from Akahi dining hall. So to begin this project, I honestly had no idea how to start. In 5th grade we did the same type of thing but our capsules could use parachutes, these ones couldn't. Therefore, because I was unsure of what to use to make this experiment successful, I decided to do a search on Youtube for ideas. I came across one girl who used three sponges, hiding the egg within a middle sponge and connecting all three using string. This mechanism worked for her, so I figured I'd give it a try. So I bought the supplies and tested my recreation and it worked!(: With that being said, my egg drop was a success, keeping my egg from breaking when thrown 3 stories. The lightness of the sponges kept the egg from falling at such a high velocity, increasing its contact time with the egg, decreasing the capsules linear momentum. I really liked this experiment, just because it was an interesting way to learn about momentum hands on. But yes I got my idea for this experiment from youtube, but its not called cheating, its called working smart, not hard (:

Quarter 2, Blogpost #6

This blogpost was supposed to be done last weekend, but once again, I forgot about it, so am deciding to make it up now. This series of pictures were taken today while I was showing my sister how to field a ball using the back hand technique. Since we were in the 10 and under division, our coaches have constantly stressed how a back hand catch is a different from a forward hand catch. When fielding a ball on your glove hand side, you want to step into the ball and catch it as soon as you can. With a back hand catch, you want to "ride" the ball and give it as much time as you can for it to settle in your glove. When "riding" the ball, you are also increasing its contact time. This week we did a balloon toss activity where Mr. Blake showed us how to catch the balloon in a way that would increase its contact time and reduce its force. This is exactly the same when it comes to back handing a ball. In these photos, you can see how instead of stabbing at the ball and trying to pick it up in front of me, I draw my hand back and upward, giving the ball a type of cushion to increase the time in which the ball makes contact with my glove, reducing the force it uses to hit my glove, bettering my chances of catching it. Back hand catches are my fav (:

Quarter 2, Blogpost #5

In addition to learning about linear momentum this week, we have also covered a second concept, impulse. Impulse is the force average multiplied by the length of time two objects are in contact and its SI units are N*s = kg* m/s. I know this example was given in the book, but my sister and I were practicing today so it seemed like itʻd be smart to just take my picture then haha (: So anyway, when the ball comes in contact with the bat, the force between the two rises rapidly to a very large value. Because it is extremely difficult to describe the way the force varies, what is looked at is the average force that is exerted by the bat and then it is multiplied by the length of time the ball and the bat were in contact. The total cycle of this scenario first takes place when the pitcher pitches the ball. The ball travels in the direction of the batter at a certain velocity. Both the bat and ball then come in contact with each other and what happens is (like I explained) the force between the two objects rise to very large values and then drops again to zero. Then the ball accelerates back toward the pitcher with a certain velocity in the opposite direction. Therefore, this is one of the easiest scenarios to help someone understand impulse.

Quarter 2, Blogpost #4

This weekend, our blogpost assignment needs to include what we learned from reading Chapter 9: Momentum and Collisions. From reading, I've gained a slight understanding of the meaning of linear momentum. Linear momentum is the product of m (mass) and velocity (v) of an object. In other words, it is the momentum of mass m moving in a straight line with a velocity v. The equation looks like this: p = mv. The SI unit for momentum is kg x m/s. For my picture example, I recreated an example that was given in the book. I had my mom drop a teddy bear and a rubber ball, consisting of the same mass m and the same downward velocity v, causing the two to hit the floor. The teddy bear comes to rest once it hits the floor. It's momentum changes from mv downward to mv upward, in the opposite direction. The rubber ball bounces back upward once it hits the floor with a velocity v. Its change in momentum is 2mv upward. Its direction changes and its momentum is multiplied by two, for its momentum going downward and upward is the same.

Quarter 2, Blogpost #3

So this is supposed to be last weekends blogpost, but I forgot to do one and was distracted ALL week by spirit week so I haven't gotten around to doing it until today. But anyway, this picture relates back to what we've been learning in Unit 4 about forces. We just recently took our Unit 4 exam and on the exam was this problem, "A 50 kg gymnast hangs vertically from a pair of parallel rings (one in each hand). If the ropes supporting the rings are attached to the ceiling directly above, what is the tension of each rope?" This problem can also be paired with the picture above of our plastic bag holder. Although the bag is attached to one rope rather than two ropes, it is similar because in both cases only one weight is being used. In the problem, the two ropes share the weight of the gymnast. In the picture, to one rope shares the weight of the bag. The answer to the problem was 250 N, because the weight of the gymnast was being split between the two ropes, creating the even tension. The rope or strap in the picture above would also have one tension (sort of like how the example problem had an equal tension) because when you have "one rope" you get "one tension".