Blog Reflection 2-17

Summary
Difficulties
overcoming the difficulties
relate it to real life


In this unit we learned about work and energy, and the relations in between the two.  Work is a function of how much force you put on an object, and the distance over which that force occurs, using the formula Work=Force x Distance.  Work is measured in Joules.  Power is related to work, in that work divided by the time (in seconds) that it takes place over will give you the power generated by that action.  For example, if you do 1000J of work over 5 seconds, that will be 200 watts of power.  Kinetic Energy is related to work, in that the work done on an object is equal to the change in kinetic energy of that object.  The formula for finding kinetic energy without knowing the work is KE=1/2 mv^2.  Potential Energy is sort of like Kinetic Energy's evil twin.  If an object has an amount of potential energy (found using the formula PE=weight x height), than as it releases that potential energy, it is transformed into kinetic energy.  Machines are devices used to decrease the amount of force it takes to do a certain amount of work by artificially increasing the distance.  However, you cannot get more work out of a machine than you put into it.

Some difficulty I had with this unit was remembering all of the different formulas.  I mostly managed to remember by simply going over them repeatedly, but I didn't quite manage to memorize the formula for potential energy.

This unit is one of the most connected to real life that we have had for a while.  It teaches us about the energy things have while they are in motion, as well as how machines function.