Unit 5 Reflection

In this unit the first thing I learned about was work. Work is the ability an object has to do something and the equation for work is force times distance. The most important thing I learned about work is that the force and distance must be parallel, otherwise there is no work being done. The units for watts are joules and since work never changes the bigger the distance the smaller the force or the bigger the force the smaller the distance. For example,

w=df
w=df
The second thing I learned about was power. The formula for power is work over time. The units for power are watts which one watt equals one joule over one second. Power measures energy. Cars are measured in horse power, and one horse power is equal to 746 watts. Therefore, it is possible to create a horsepower if you can create 746 watts of power.
The third thing I learned about was kinetic energy. Kinetic energy is the amount of energy an object is using and is directly related to not only work but potential energy. The kinetic energy of an object depends no the mass of the object as well as its speed. The formula for kinetic energy is 1/2 times mass times velocity squared. This means that if the velocity is tripled, the kinetic energy will increase nine times because the velocity is squared. The relationship between work and kinetic energy is that the change is kinetic over time equals the work done. The relationship between kinetic energy and potential energy is that the higher an object goes, the more potential energy it has. The lower it goes/falls the more potential energy it looses and kinetic energy it gains. The formula for finding an objects potential energy is mass times gravity times height.
    The fourth thing I learned about was the Law of Conservation of Energy which states that energy cannot be created or destroyed, it may be transformed from one form into another, but the total amount of energy never changes. This means that in a car the energy used to move the car forward does not disappear it is mearly converted into heat.
    The fifth thing I learned about was machines. Machines help lower the force needed to move an object. The big thing about machines is that there is a work in and a work out. The work out is what force and distance you would have to do without a ramp or a pulley and the work in is the smaller force and bigger distance you would have to do with a ramp or a pulley.
     What I have found difficult about what we have studied this unit is keeping all the different formulas straight and remembering that the change in kinetic energy equals work and not just the kinetic energy. I over came these difficulties by doing problems in class and memorizing which formulas were associated with which concepts so I knew which ones I needed to use. My problem solving skills and effort this unit have not been as strong as they usually are. Though I have completed all my homework and really tried to understand our activities, I have not been persistent in learning the materials and my self-confidence lowered as a result because I did not do very well on quizzes.
     My goal for the next unit is to be persistent in learning things that may prove to be difficult and memorizing the formulas right when we learn them so that I do not struggle throughout the unit and instead can attack each new concept with out having to worry about the last.
     The connections that I can make to the real world are with the three flights of stairs every day versus the elevator on the other side of the building. It is good to know that I get a work out instead of a work in. Another connection I can make is to cars, both with the law of conservation of energy and power. Since my dad is a car dealer I know a thing or two about the engine and it is interesting to understand that the reason cars aren't 100% efficient isn't because any energy is wasted but rather because it is converted into heat.