Week 31 Reflection

I was not here for a lot of the important things that we learned about light this week.  From reading Geoffrey's blog I know now that we learned about the electromagnetic spectrum (I actually do remember being taught this).  We also learned that humans can see only three colors which are red, green and blue.  We also learned about how light refracts and reflects through and off of surfaces.

The electromagnetic spectrum consists of the longest waves to the smallest waves.  It goes radio, microwaves, infrared, visible, ultraviolet, x rays and finally gamma rays.  We only see a tiny fraction of the entire electromagnetic spectrum. 

According to Geoffrey's blog, we can only see blue, red and green.  But when you combine the colors, that's when you start to get the different hues and colors.  I also know that if something is in front of a light source, it will create a shadow because it is blocking the light waves from shining there.

Also from Geoffrey's blog light can refract and reflect.  When light refracts, it bends.  When light reflects, it bounces off of a surface.  Refraction mostly happens in water.

Week 30 reflection

I missed three class periods this week because of AP tests and such.  So I can only talk about a few things for week 30.  What we did do this week is learn about sound waves.  We also went outside and did an experiment with the cement decorations outside to show how the waves bounce off and amplify.

We learned that the speed of sound is about 356 meters per second ( I think I may be wrong but that's what I thought it was).  We saw that distance affected when you saw the sound and when you heard it.  We watched a video where Steve Elliot was clapping wood blocks together and was walking backwards.  The farther he got down the field, the later the sound came after we saw him clap the blocks together.

The experiment that we did this week was we went outside to the cement decorations outside of the school and talked to them.  What happened was it amplified our voices and made sound like we were talking into a microphone.  We were told that when you talk into a space that can bounce the sound waves together, what you get is an amplifying affect that makes the sound louder.

I thought that this week I got what was being taught to me.  Even though I missed a majority of class this week, I feel like I still learned something.  I thought that the microphone experiment was cool because I didn't think that it would work.

Week 29 Reflection

This week, we started a new unit on waves.  We learned about transverse and longitudinal waves.  Also how  those wave can either have measures of amplitude, frequency and wavelength or compression and rarefactions.  To demonstrate these measurements, we did an experiment with slinkies and we watched the energy go through them.

We learned that longitudinal waves are like slinkies.  The movement is in the same direction that the energy is being transferred.  Longitudinal waves go through compression (shrinking) and rarefaction (expanding).  You can see the compression and rarefaction in slinkies if you send a pulse of energy through them. 

Transverse waves are different from longitudinal waves in the way that their movement goes up and down while the energy goes straight through them.  These are the waves where you can measure things like amplitude and wavelength.

The experiment that we did this week was where we took slinkies and waved them side to side.  It created a transverse wave.  From that we measured the period for one wave to go through the slinky. 
We could even measure the amplitude if we wanted to because we could see how big the wave got.

I think I did alright this week.  I get most of what we've been taught about waves so I figure that I'm in good shape.

Week 28 Reflection

This week we learned more about momentum and the transfer of energy.  We also used this new thing called gosoapbox that I thought was a great idea personally.  It was nice that throughout the class period you could answer questions about the lesson that the teacher puts up there.  I remember that we had to do a lab that involved using that website and looking things up online.  I think that it's a great idea. 

The entire week we were working on our Newton Cradles.  They were due on Thursday and we had to present them on Friday.  I think Devin and I's project worked pretty well.  We used ping pong balls that had needles stuck in them for eyelets for the string.  We cut out an old shoebox and used that for the frame.

We were told that the more rigid the object is, the more efficiently it transfers energy.  Even though ping pong balls are necessarily the most rigid objects, the still transferred the energy well.  We could do all the tricks that we were supposed to do.  We could drop 1, 2 and both ping pongs from both ends and have good results.

This week also involved the new soapbox website that we used.  The lab that we had to do with it involved us watching a video that Mr. Abud made I think explained what an impulse was and then he asked us a question at the end that we had to answer on twitter. (I'm taking that from memory, so I am probably wrong but that's what I thought it was talking about.)  I feel like we should use gosoapbox more often.

Week 27 Reflection

This week was all about momentum and energy transfer.  We have a project that is due on thursday that involves us making a Newtons Cradle to demonstrate what we are learning.  We also worked with the cars on the track to demonstrate how momentum is transferred to another object. 

Momentum is the movement after a force has been applied to an object.  So if I push a ball on the floor and nothing else pushes the ball afterward, its momentum is carrying it.  We also did work with "Momentum Blocks".  You take the velocity of the object in meters/seconds and put that one side of the block and then you take the mass in kilograms and put it on the other side and multiply them.  That is how you get your momentum in kg/meters/second.

This project that we are doing will be a good way to demonstrate transfer of momentum.  The more rigid the spheres are, the better the transfer.  I know that if you apply a force to a sphere (in this case gravity) it will hit the sphere next to it and start a transfer in momentum until it reaches the last sphere which isn't blocked by anything.  This is where it gets its motion from.

This week we also worked with the cars on the tracks to demonstrate what the transfer of momentum looked like with two things that could freely move and weren't blocked by anything.  We pushed one car into the other and observed what happened.  What happened was usually the car that was hit would take off and the other car would stop completely.  This is because the car that was hit took all of the energy and left the other car with nothing.

I think that this week was very succesful.  I believe that I got everything that was taught to me.  I'm pretty sure that I had some trouble with certain things on the exam, but I think I did fairly well, just by judging from taking the test.

Week 26 Reflection

This week we learned more about energy and how to calculate it.  We learned what joules, watts and power is.  We also used the results of an experiment that we did last week to get practice on finding joules, watts and power.  The experiment was where we had our class run up the stairs in groups and time themselves.  Using these measurements, we could find joules, watts and power.

We learned that joules are a measure of energy.  You find it by doing the equation massXgravityXheight.  To get watts you just divide that whole equation by the time.  Finally to get the horsepower, you multiply the watts by 0.0013.  We also learned that power is a rate of joules/time.

The experiment where we had people run up the stairs really helped me learn about joules, watts and horsepower.  Everyone timed how fast they could run up the stairs and we put everything into the equation to get joules.  It all started to make sense to me when everything had a place in its equation and we could get a number that represented the energy.

We also had an assesment this week.  It was about everything that we had learned about energy.  I was very thankful for the review the day before because there were still some things that I hadn't really understood up until then.  Things like the fact that power is a rate and not a unit and the difference between power and work.

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.