CK-12-Physics - Intermediate

(Marvins-Underground-K-12) #1

6.4. Power http://www.ck12.org



  • The conservation of mechanical energy can be written as:KEi+PEi=KEf+PEf

  • In the presence of dissipative forces the conservation of energy can we written as:

  • KEi+PEi=KEf+PEf+Qf, whereQfis the energy that has been transformed into heat.

  • In the event of an explosion, heat,Qi, is added to the initialKEandPEenergies and in the most general case,
    heat can also be lost,Qf, after the explosive, thus:

  • KEi+PEi+Qi=KEf+PEf+Qf

  • The average power is the rate at which work is done or consumed or produced :P=Wt =(F xt)=F vand has
    units of Watts(W)

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