Sunday, March 24, 2013

Week 24 Reflection

1. Some factors that could have made the boat sink: if the tape was not pressed on tight enough or was coming off in some places.  This could expose seams that let water in.
If there were any cuts in the cardboard. This could disable the waterproof outside by letting the inside meet water.
If it was not stable enough to handle the weight of two people.  This could cause the boat to sink because of the sheer weight from the people.

2. To stay afloat, you must have a wide enough base to distribute the weight of the sailors.  You must also duct tape every seam so that water has no chance of getting into your boat and sinking it.  Also, having a flat bottom helps to distribute the weight and make it easy to climb into and keep in balance.

3. The knowledge of the lowest center of mass is most stable is very important because the captain is in charge of directing the building of the boat, so making a design that includes that principle is essential for making the boat float.

4. Our groups boat sunk at the starting line due to small cut that had appeared in the side of the box.  We didn't have any ductape to fix it with, and it ended up being our downfall.  Other than that, we had a very strongly built boat.

5. I think that the best rowing technique is to have the two sailors alternate on which side they paddle.  This way, it keeps the boat fairly straight.

6. What I would do differently is that I would put pieces of cardboard on the creases in the cardboard and tape them to have an even stronger frame for the boat.  And pack extra ductape.

Sunday, March 17, 2013

Week 23 Reflection

This week we mostly discussed how energy is transferred to different objects.  We used a demonstration with a bowling ball and a string to show how energy dissapates.  Also, this weeks lab was testing to get measurements on a car that bounced off of walls on each side of the track.

The demonstration showed that energy will constantly leave an object if no other force is acting on it.  If you swing a bowling ball by a string and release it from a certain point, it will not return to that point because some of the energy had dissipated from it and it is not swing with as much force as it originally had. 

We also learned that you can feel, hear and even see energy dissapating into another object.  Like if you get hit with a ball, the bruise that you get is a result of the energy from the ball affecting the nerves in your arm.  You can see energy dissipating by seeing if another object moves after being hit by something else.  Hearing energy dissipate is like when you shoot a basketball and it makes a clanking sound off of the rim because you missed. 

This lab that we did this week involved us measuring the distance traveled by a car on a track that bounced off of walls.  We had to measure the distance within two seconds.  Then we had to make LOL graphs that showed where all the energy was at the time of each of the 5 trials.  This lab helped me get that the more potential you put into something, the farther it will go.

I believe that I get everything thats being taught this week.  I found it really interesting that dissipated energy came in the form of sound.  Actually, this whole energy unit that we're doing now is pretty interesting.

Sunday, March 10, 2013

Week 22 Reflection

This week is kind of hard to write about since the lowerclassmen had their tests this week.  But we did investigate more about how to build our cardboard boats.  We also had a lab at the end of the week that allowed us to experiment with surface area and the amount of weight it holds.

I was told this week that if we have a wide surface area on our boats, it will be able to hold and distribute the weight better.  But, if it's too wide and there is not enough weight it will sit on top of the water.  This will make it hard to steer since there is no water pressure.  If it sits to far under the water, then it will be to hard to steer because of all of the waters force on the boat.

This lab that we did on friday was a great example of how the boat takes and distributes weight.  If you had a large surface area and a strong bottom, then it would stay afloat.  You had to make sure that all of the seams were sealed because water leaking in was the boats downfall.

I believe that I have an idea of what I want our boat to look like.  I know that it should have a flat bottom to hold our weight.  It should also sink just far enough into the water to give us enough pressure to steer.

Sunday, March 3, 2013

Week 20 Blog Reflection

This week we spent a lot of time dicussing the topic of the centripital paths of the moon and the earth around the moon.  We tried to get if the moon orbited around the earth or the sun.  To demonstrate this we tried to use some kids from our class and have them move like cars passing each other in lanes.

So from all of the discussing that we did this week, we learned that the earth orbits the sun.  The moon also orbits the sun.  We learned that the path of the moon makes a certain "flower" shape if we trace it.  It is constantly being pulled by the sun and then pulled back by the earth.  So the path of the moon is not orbiting the earth, rather it's always "speeding" past the earth and then "slowing" down and getting back in the fast lane.

The demonstration that we did for this concept was we took kids from our class and we had one be the sun, and the other two be the moon and earth.  We had the earth student orbit the sun at a constant speed.  Then we had the moon student go on the outside and pass the earth, then move in between the earth and sun and slow down.  This would continue to make the moons path.

This week was pretty successful I think.  I now know that the moon, along with the earth, revolves around the sun.  All of the other things that we were being taught this week I understand well, so I don't really have any questions yet.  The coolest thing about this week is that we were talking about centripital motion with a car attached to a string and now we're talking about centripital motion with things as big as planets.