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hitman0097
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Homework Statement
An automotive battery has an emf of 11.1 V. When supplying power to the starter motor, the current in the battery is 20.0 A, and the terminal voltage of the battery is 10.6 V.
a.)How much power is delivered by the battery due to the chemical reactions within the battery when the current in the battery is 20 A?
b.)How much of this power is delivered to the starter when the current in the battery is 20 A?
c.)By how much does the chemical energy of the battery decrease if the current in the starter is 20 A for 6.9 s?
d.)How much energy is dissipated in the battery during those 6.9 seconds?
Homework Equations
P=(E)(I);where E is the emf
Ps=VI; power to the starter V=10.6 in this case.
E=Pt; t is time P is (E)(I) power
Q=(P-Ps)t; the energy would be dissipated in the form of Heat (Q)
r=[tex]\Delta[/tex]V/I; internal resistance inside the battery, delta V would be 11.1-10.6
Not sure if internal resistance is needed I didn't use it. but it might be needed
The Attempt at a Solution
P=11.1*20=222W? or kW? got it wrong so I tried 222^-6 kw wrong
Then I am just lost, any help would be greatly appreciated