How Does the Energy Density of a Lead-Acid Battery Compare to Gasoline?

In summary, potential energy in fuels is the stored energy that can be released during a chemical reaction. Examples of potential energy in fuels include gasoline, natural gas, coal, and wood. It is typically measured in joules (J) or kilojoules (kJ), but can also be measured in British Thermal Units (BTUs) or calories (cal). Factors such as chemical composition, physical state, and temperature affect the amount of potential energy in a fuel. This energy is crucial for everyday activities such as transportation, cooking, heating, and electricity production.
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aaronb
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Homework Statement


A fully charged 15.0 kg lead-acid battery can deliver power 1450 W for 1.0 hr. (For comparison, the "heat of combustion" of gasoline is about 44 MJ/kg.)

Battery _____ MJ/kg

Homework Equations


Unit conversion problem
1W = 1 J/s

The Attempt at a Solution


(1450 J/s / 15kg) = 96.7/10^6 = 9.6 *10^-5
 
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MJ/kg


The potential energy in fuels, such as gasoline, is often measured in terms of its heat of combustion, which is the amount of energy released when the fuel is burned. In this case, the "heat of combustion" of gasoline is about 44 MJ/kg. This means that for every kilogram of gasoline, approximately 44 MJ of energy can be released.

In comparison, a fully charged lead-acid battery with a mass of 15.0 kg can deliver a power of 1450 W for 1.0 hour. Using the equation 1W = 1 J/s, we can convert the power to energy by multiplying it by the time, giving us 1450 J/s * 3600 s = 5,220,000 J of energy.

To determine the potential energy in the battery per kilogram, we divide the total energy by the mass, giving us 5,220,000 J / 15 kg = 348,000 J/kg. This is significantly higher than the heat of combustion of gasoline, indicating that batteries have a higher potential energy storage capacity compared to fuels like gasoline.

In conclusion, the potential energy in a fully charged 15.0 kg lead-acid battery is approximately 348,000 J/kg, which is significantly higher than the heat of combustion of gasoline. This highlights the potential of batteries as a more efficient and environmentally friendly energy source.
 

FAQ: How Does the Energy Density of a Lead-Acid Battery Compare to Gasoline?

What is potential energy in fuels?

Potential energy in fuels refers to the energy stored in a substance that can be released when the substance undergoes a chemical reaction, such as combustion.

What are some examples of potential energy in fuels?

Examples of potential energy in fuels include gasoline, natural gas, coal, and wood. These substances contain chemical bonds that can release energy when broken during a chemical reaction.

How is potential energy in fuels measured?

Potential energy in fuels is typically measured in joules (J) or kilojoules (kJ). It can also be measured in British Thermal Units (BTUs) or calories (cal).

What factors affect the amount of potential energy in fuels?

The amount of potential energy in a fuel is affected by its chemical composition, including the type and number of atoms present. The physical state of the fuel (solid, liquid, or gas) and its temperature also play a role in determining its potential energy.

What is the role of potential energy in fuels in everyday life?

Potential energy in fuels is essential for many everyday activities, such as transportation, cooking, and heating. It is also used in the production of electricity, powering everything from light bulbs to electronic devices.

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