A certain car battery with a 12.0 V emf has an initial charge of 131 A · h. Assuming that the potential across the terminals stays constant until the battery is completely discharged, for how many hours can it deliver energy at the rate of 130 W?

Question

Jessie

Physics

21 October, 14:46

A certain car battery with a 12.0 V emf has an initial charge of 131 A · h. Assuming that the potential across the terminals stays constant until the battery is completely discharged, for how many hours can it deliver energy at the rate of 130 W?

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Answers (1)

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Cory Bright · Answer 1

The battery can supply 130 W for 11.75 h

Explanation:

In order to discover the time in wich the battery can supply this energy we need to find how much current is being drawn from it, we do that by using the equation for real power that is P = V*I, since we have V and P we can solve for I as seen bellow:

I = P/V = 130/12 = 10.834 A

We can use this value to find how many hours the power can supply said current. We do that by dividing the current capacity of the battery by the current drawn:

t = 141/12 = 11.75 h