Sunday, February 10, 2013

Voltage and the iPad




    ~This week we talked about voltage, electricity, and charge. Atoms are generally neutral meaning there is a balance of protons and electrons. Only electrons move from atom to atom. Protons stay put. More electrons means the atom is negative. Less electrons means it is positive. 
     To transfer charge, there is friction. Like charges will repel and opposites attract.
          Protons will be more attracted to electrons, and will do its best to repel other protons.

     ~Voltage is a field (force at a distance) that surrounds charged objects. It is the "mountain" and "space" between two object that allows for the flow of electricity. "Voltage is to electricity as height is to gravitational potential energy.
          Electric potential=Voltage
          Electric Potential Energy = (charge)(voltage)
The higher the voltage and more charge means greater U sub e. 

Real World Connection: 
     Apple chose to use the lithium-ion battery to run their devices. They use lithium because it has a high power density that gives a longer battery life. Every time a battery goes through a full charge cycle, it slightly has a smaller capacity. This is maybe because there are less and less chemical reactors. You are able to charge the lithium battery a large amount of times but it is finite. The iPad charger is 5.1 Volts meaning it has an electric potential capacity of 5 V.

http://www.apple.com/batteries/