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A car battery has a rating in ampere-minutes, allowing estimation of the time it can deliver a specific current before discharge. Calculate the energy stored in a 50-ampere-minute, 12-volt battery. Secondly, presuming 100% efficiency in energy conversion, determine the volume of water required from a 50cm-high hydroelectric dam to charge the battery.

a) 7200 Joules
b) 3600 Joules
c) 1800 Joules
d) 900 Joules

User ESL
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Final answer:

Car batteries are rated in ampere-hours (Ah), which corresponds to charge capacity. The energy stored in a 50 ampere-minute, 12-volt battery is 36,000 Joules (J). Assuming 100% efficiency, the volume of water required from a 50 cm-high hydroelectric dam to charge the battery is 7200 liters.

Step-by-step explanation:

Car batteries are rated in ampere-hours (Ah), which corresponds to charge capacity. The energy stored in a battery can be calculated by multiplying the charge capacity (in Coulombs) by the voltage difference across the battery. In this case, the battery has a rating of 50 ampere-minutes (A·min) and a voltage of 12 volts (V).



To find the energy stored in the battery, we first convert the charge capacity from ampere-minutes to Coulombs:



50 A·min x 60 s/min = 3000 C



Then we calculate the energy using the formula:



Energy (E) = Charge (Q) x Voltage (V)



E = 3000 C x 12 V = 36,000 J



Therefore, the energy stored in a 50 ampere-minute, 12-volt battery is 36,000 Joules (J).



Secondly, presuming 100% efficiency, we can determine the volume of water required to charge the battery. Since 1 Joule of energy is equal to 1 liter of water lifted by 10 cm, we can calculate:



Volume of water = Energy / (Density x g x height)



where Density of water (ρ) = 1000 kg/m3 and g is the acceleration due to gravity (9.8 m/s2).



Using the given energy of 36,000 J and height of the hydroelectric dam of 50 cm:



Volume of water = 36,000 J / (1000 kg/m3 x 9.8 m/s² x 0.5 m) = 7200 liters



Therefore, the volume of water required from a 50 cm-high hydroelectric dam to charge the battery is 7200 liters.

User Nick Entin
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