Sunday, February 21, 2010

Energy Reflection

Part A:
This is what i have learned about energy and the conservation of energy. Energy is a conserved, substance- like quantity with the capability to produce change. Energy can be stored in numerous ways: elastic energy, kinetic energy, gravitational potential energy, chemical potential energy, and internal energy (usually friction). Kinetic energy is the energy an object has when it is moving, where gravitational potential energy is when an object is at a height. Energy can also be transformed into heat and sound. Although the energy may be transferred to another type of storage, it is always constant. Energy does not grow(gain more) or lose any of the amount, it just changes form. While learning about energy, we also learned about work. Work is the energy transferred by forces, causing a displacement. This work is just a change in the energy by a force, like a person pushing a box. The work is done by the person pushing.While learning about work we also learned about power. Power is the rate of work, always in watts. I have also learned about Energy Flow Diagrams. These diagrams show the energy and how it is stored at the beginning and the end. The system is also showed in the diagram. Energy Flow Diagrams are all qualitative, so after learning how to do those we learned many equations to solve the problems with quantitative answers.
I believe this unit is fairly difficult. I always confuse equations and forget which ones work best for certain problems. I sometimes have to try a few equations, but am usually able to solve the problem. The Energy Flow Diagrams are very helpful, and help me know which equation to use because I can see which energies I am looking for. When the energy changes form, it can be hard for me to see which form it ends up as. This is becoming easier for me as I do more problems.
I think my problem solving skills could be a little better, but have definitely improved. I am getting better at quickly finding the right equations after looking at the problem. When I see a difficult problem, I now see how I can solve it and try equations until I do. I believe with a little more practice, especially on power and work problems, my problem solving skills will be a lot better.
Part B:
Energy is everywhere in our world. When a car is going to when a car stops, there is a transfer of kinetic energy to internal energy (from friction). When a little boy is pushing a toy around on the floor, there is work (force). When a person jumps off of a cliff to go bungee jumping, the energy transfers from gravitational potential energy to kinetic energy. Energy is everywhere in our world, always there, just changing forms all the time.

Monday, February 1, 2010


How do snowboarders move so smoothly?
This is a glog that shows how forces and mtion cause snowboards and snowboarders to glide over the snow. It explains the friction and forces at work, and how they apply to the snowboarder. Snowbaords and the snow creatwe little friction, and this exlains how and why.
click here