Week 10 Reflection

This week the big project was building our bridges.  We worked on them all week and then we showed them to the class on monday and tuesday.  There were many different looking bridges that ranged from large and bulky that weighed alot, to the simple lightweight designs.  I know that we had to get the best ratio from the weight of our bridge to how much it could hold. 

Building my bridge wasn't too hard.  I came up with the design in my head and then made a bridge out of it.  I made almost a floor of spaghetti and taped them all together and then made another "floor" spaghetti and taped them together to make the base of the bridge.  I put a brace under the bridge to distribute the weight.  I also used braces that go on the sides to distribute the weight even more.  They were triangle patterns that touched at certain points on the bridge.

I thought my bridge did alot better than what I expected.  It held alot more weight than I thought it was going to hold.  I forgot how much it actually held but it didn't break until the blocks were stacked pretty high.  Plus, the bottom didn't break, the blocks all fell off.

Overall, I liked the bridge project.  It was a good way to put what we were learning into action.  The only regret that I have is that I wish that I had built my bridge stronger and more sturdy so it could support more weight.

Week 10 Reflection

This week we learned more about force pairs and how to draw force diagrams with component forces and how to make a quantitative force diagram. 

To demonstrate force pairs, we used the force plates.  We made two students hold and push against each other with the plates.  Then we would check the graph.  They would always be the same amount of force pushing against each other.  Even when we had one student in a rolly chair and another student on their feet and push hard enough to make the chair roll.  It didn't matter because the same amount of force would push back on the opposing force plate.

We learned how to draw more complex force diagrams such as adding in strings holding up an object, objects falling with or without air resistance, etc.  An example would be drawing a force diagram for a freefalling skydiver with no parachute with no air resistance acting upon the person. You would draw an arrow pointing straight down because gravity is the only thing acting upon the skydiver.

We also learned about quantitative force diagrams.  They are not to much different than regular force diagrams other than you need to label how much force is acting upon in object, usually in newtons.

This week I think I did pretty well in participating and listening well.  I think that I get most of the stuff that is being taught to us and I improved on doing the force diagrams right. 

Week 9 Reflection

This week we went more in depth with force diagrams.  The force diagrams were more in depth because there were slopes with either friction or no friction acting on the object.  We also had to show where the forces were acting on the object such as a slope diagonally pushing on an object instead of just straight up and down like with the force of a table.  I also know what a force pair is now.  They are forces that, when usually pulling on each other, will have the same amount of force pulling on each other. 

To demonstrate how force pairs work, we took two pulley systems and hooked them together.  Both of these mechanisms measured how much force was pulling on them.  We had two people pull on them and we looked at the measurements.  They both read the same amount no matter who pulled harder or if you were walking or whatever.  The forces were the same no matter what.  No person could really "pull harder" anyways since the person who was not pulling as hard has to use more force to stop the springs from getting yanked from their hands.

This week we had an assesment on Wednesday and it involved more complicated force diagrams.  We had to label every force that was acting on an object.  Those forces include the push of the table/slope, earth, and it's momentum either with or without friction.  We had to make sure to see if they were balanced forces by phrases like "at a constant speed" or something like that. 

The biggest concern that I have is about the force diagrams.  I still don't know how to label the forces if friction is involved.  Other than that I think I have a good understanding of what the material that were learning in class is about. 

Week 8 Reflection

During this week we learned about component and resultant forces and we went even more in depth with force diagrams.  We learned that component forces are the ones that make up the whole or resultant forces.  We also learned more about accurately drawing force diagrams.  We started to include newtons and kilograms in our diagrams.

I know that to demonstrate component and resultant forces we had a big, circular wooden board and we hung strings with weights off of the sides.  When the string was lined up at certain degrees, such as north and east, we know that the direction that it will fall will be northeast.  The component forces, north and east, will produce the resultant force of northeast. 

We also learned what center of mass was.  To demonstrate center of mass, we had people stand up and show that they could bend over and pick up a chair or a pencil with no trouble at all.  Then we had them lean against the wall and show that they can't do anything to balance their center of mass because the wall is stopping them.  Another interesting demonstration was we had four people sit on chairs and lay on each others laps.  Then, we took away the chairs and they all balanced each other out.  It was because their center of masses were all balanced on each other.   

Overall, this week was pretty productive.  I get what center of mass is but I still need to learn more about it because I just know what it is, I can't really apply it to anything yet.  Component forces and resultant forces were pretty easy to get and again with the demonstrations and visuals, it was easy to grasp.