Scholars have pondered upon the question for centuries. Why when I ride my skateboard do I decelerate faster on dry concrete rather than wet concrete? I'm going to try to answer this question using a video and many diagrams. Click on the link below to see my glog that answers this question.
skateboard
Note: Because of the comments left about this post I have edited my glog to have a note about the difference between the friction I used for my experiment versus the friction of rolling wheels. However, when I looked up the physics of rolling wheels it involved many equations and terms that we have not studied. Therefore I put a brief note at the bottom of my glog about the subject. You will find it if you scroll down on the sticky at the bottom of the page. Thank you.
Atributions:
http://www.exploratorium.edu/skateboarding/trick.html
http://books.google.com/books?id=BwistUlpZ7cC&pg=PA282&lpg=PA282&dq=physics+of+skateboarding+rolling+wheels&source=bl&ots=7ZpnfY1MnS&sig=qzQjsNnTdLVumdEYZCigY1ex5Zo&hl=en&ei=atFoS5HMNMiVtgevhdXYBg&sa=X&oi=book_result&ct=result&resnum=2&ved=0CAkQ6AEwAQ#v=onepage&q=skateboard&f=false
Monday, February 1, 2010
Tuesday, January 26, 2010
Circular Motion Reflection
What I learned about uniform circular motion is that it is the motion of an object in a circle with a constant speed. Even though the object has a constant speed that doesn't mean the object isn't accelerating. Because the object would be changing direction, it would have an acceleration as well. This acceleration is called the centripetal acceleration. Probably the most important thing I learned about circular motion is the centripetal force. This is the inward force that must be applied to an object to keep it moving in a circle. Before this unit, I would get off a roller coaster at Six Flags and say, "man, could you feel that centrifugal force?" Now I know better and have learned that the inward force keeping me in my seat was actually the centripetal force.
What I found most difficult about what I have studied was deciding which equation to use. Given that the variables in the three equations were so similar, I had a hard time making sure I was using the correct equation. But of course, with practice I improved at this and now know the differences with each equation. For instance, I should only use the equation v = 2(pi)r/T when I can figure out the period. Even though some parts of this unit were hard I tried my best to figure them out.
My problem solving skills after learning about circular motion have improved because I have learned how to deal with problems that I can't get at first. Some problems that I have come across involving circular motion to me seemed to be too difficult. However, once I challenged myself to take on these kinds of problems I sometimes got the correct answer which helped my problem solving skills by getting me used to harder problems.
What I found most difficult about what I have studied was deciding which equation to use. Given that the variables in the three equations were so similar, I had a hard time making sure I was using the correct equation. But of course, with practice I improved at this and now know the differences with each equation. For instance, I should only use the equation v = 2(pi)r/T when I can figure out the period. Even though some parts of this unit were hard I tried my best to figure them out.
My problem solving skills after learning about circular motion have improved because I have learned how to deal with problems that I can't get at first. Some problems that I have come across involving circular motion to me seemed to be too difficult. However, once I challenged myself to take on these kinds of problems I sometimes got the correct answer which helped my problem solving skills by getting me used to harder problems.
Saturday, January 9, 2010
Fig Newton's Second Laws Questions
What I have learned about Newton's second law of motion is that the acceleration of an object is proportional to the net force. The equation that shows this is Sigma F = ma. The net force is in newtons. This is important because it shows the connection between the cause of an object moving which is the net force and the effect of an object moving which is the acceleration. This also creates friction in the system. I have learned how to apply this concept to things like an Atwoods machine as well and have widened my knowledge of how the acceleration of an object is related to that object's force.
What I have found most difficult about what we have studied is drawing the FBD's for the Newton's second law problems and figuring out how to make an FBD into an equation. This gets even harder when there are two or even three FBDs involved. Despite this, however, I have been able to get a grasp on how to figure out the equations from the FBDs and it hasn't been that much of a problem.
My problem solving skills have definitely improved because of this unit. Some strengths of my problem solving would probably be applying the techniques from simple problems to harder ones to help complete them. This strategy has helped me solve many problems that I thought I couldn't do. A weakness of my problem solving skills would probably be not figuring out how to use the FBD to make an equation. Finding the net force from the FBD can sometimes be very difficult for me. Even though I have my weaknesses with problem solving I believe that this unit has helped my problem solving skills.
What I have found most difficult about what we have studied is drawing the FBD's for the Newton's second law problems and figuring out how to make an FBD into an equation. This gets even harder when there are two or even three FBDs involved. Despite this, however, I have been able to get a grasp on how to figure out the equations from the FBDs and it hasn't been that much of a problem.
My problem solving skills have definitely improved because of this unit. Some strengths of my problem solving would probably be applying the techniques from simple problems to harder ones to help complete them. This strategy has helped me solve many problems that I thought I couldn't do. A weakness of my problem solving skills would probably be not figuring out how to use the FBD to make an equation. Finding the net force from the FBD can sometimes be very difficult for me. Even though I have my weaknesses with problem solving I believe that this unit has helped my problem solving skills.
Saturday, December 5, 2009
Fig Newton's first Law questions
This is what I learned about inertia: Inertia involves two conditions of equilibrium. The first is Translational equilibrium. A body is in this equilibrium when its vector sum is equal to zero. This means that Sigma Fx = 0 and Sigma Fy = 0. The next condition of equilibrium is Rotational equilibrium. An object is in this when the sum of the forces and torques acting on it are zero or
Sigma t = 0.
What I have found difficult about what I have studied is trying to remember what I learned in class and use it on the homework. During the first night after I learned something in class I find it hard to understand the homework the way I did in class. However, after practicing how to do the problem I can do them more easily.
My problem solving skills have significantly increased since the beginning of the inertia unit. This is partly because I could understand the previous unit very well where as in the inertia problems I had to seek help from friends and practice a lot to get a secure understanding over the material. Through this frequent practice I began to increase my problem solving skills. My strength in my problem solving skills would probably be figuring out the equation to use while my weak point might be my FBD's.
A connection I can make with what we have studied and the real world is skateboarding. A traditional board has two trucks about 6 inches from each end. Using my weight and rotational equilibrium I can find the force exerted by each truck.
Sigma t = 0.
What I have found difficult about what I have studied is trying to remember what I learned in class and use it on the homework. During the first night after I learned something in class I find it hard to understand the homework the way I did in class. However, after practicing how to do the problem I can do them more easily.
My problem solving skills have significantly increased since the beginning of the inertia unit. This is partly because I could understand the previous unit very well where as in the inertia problems I had to seek help from friends and practice a lot to get a secure understanding over the material. Through this frequent practice I began to increase my problem solving skills. My strength in my problem solving skills would probably be figuring out the equation to use while my weak point might be my FBD's.
A connection I can make with what we have studied and the real world is skateboarding. A traditional board has two trucks about 6 inches from each end. Using my weight and rotational equilibrium I can find the force exerted by each truck.
Tuesday, November 10, 2009
Monday, November 9, 2009
Welcome to my blog! If you want to learn about acceleration then click on the link below to see my acceleration glog.
Acceleration Glog
These are my Attributions for my Glog:
http://zuban.com.ua/blog/documentum/flying-squirrel-developer
http://www.iaogallery.org/benefits/reddot/reddot07.htm
http://falcon.physics.uww.edu/survey/sonitype.html
http://www.tutorvista.com/content/physics/physics-iii/kinematics/velocity-time-accelerated-motion.php
special thanks to voki and wordle
Acceleration Glog
These are my Attributions for my Glog:
http://zuban.com.ua/blog/documentum/flying-squirrel-developer
http://www.iaogallery.org/benefits/reddot/reddot07.htm
http://falcon.physics.uww.edu/survey/sonitype.html
http://www.tutorvista.com/content/physics/physics-iii/kinematics/velocity-time-accelerated-motion.php
special thanks to voki and wordle
Thursday, October 29, 2009
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