Tuesday, September 9, 2008

Connections between potential and kinetic energy

Oké, I start back after a sad weak of getting used to school again. But that won’t stop me (to long).

Today, we continue with an expansion of the last topic: Energy. When we ignore the energy an object contains because of it’s mass, we can say the sum of the potential energy of an object and it’s kinetic energy will always remain constant, if no energy is added to it? For example, if you kick an object, you add energy to it. But if you let an object drop down from a certain hight, it’s potential energy is converted into kinetic energy. The same when you take a run-up with your bike and then ride up a hill. Only, here, the kinetic energy you had by riding your bike (and thus by adding energy to yourself and the bike) is converted to potential energy. Slowly, your bike slows down, and when you stop, all the kinetic energy has turned into potential energy (disregarding friction). You can use this potential energy to make speed again when you ride down again. So, we can say:

Ep + Ek = k

Oké, so fare, you only have to know this. Next time, I’ll explain how to calculate the size of these energies. Take care.

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