Question

Travel Your family car travels 20 miles on one gallon of gas. You visit your friend who lives two miles away three times a week. Calculate how much gas you would save in five weeks if you walked or rode your bike to your friend's house. Estimate how much gas you would save in one year.

Short answer

You would save 3 gallons in 5 weeks and approximately 31.2 gallons in a year.

Step-by-step solution

Calculate Weekly Gas Usage Driving to Friend's House

First, we need to determine how much gas is used per week when driving to your friend's house. Each visit round trip is 2 miles (there and back), totaling 4 miles per visit. Since you visit three times a week, that's 3 visits times 4 miles, equating to 12 miles driven per week. Since the car travels 20 miles on one gallon of gas, the gas used per week is \( \frac{12}{20} \) gallons.

Calculate Gas Saved Over Five Weeks

Now, calculate the total gas that would be saved over five weeks. Multiply the weekly gas usage by five: \( \frac{12}{20} \times 5 \) which equals \( \frac{60}{20} = 3 \) gallons saved if you don't drive to your friend's for those five weeks.

Calculate Annual Gas Savings

To estimate the gas savings in one year, consider that there are approximately 52 weeks in a year. Thus, calculate the yearly savings by multiplying the weekly gas usage for the visits by 52 weeks: \( \frac{12}{20} \times 52 \approx 31.2 \) gallons saved by not driving to your friend's house for the whole year.

Key concepts

Gasoline Consumption Calculations

Understanding how much gasoline your car consumes can help you make better travel decisions and save money. The rate at which a car uses gas is known as fuel efficiency, usually measured in miles per gallon (mpg). If your car has a fuel efficiency of 20 mpg, this means it can travel 20 miles using one gallon of gasoline.

To calculate how much gas you use for specific trips, you need to know the distance you'll drive. Consider the example of visiting a friend who lives 2 miles away. Each round trip is 4 miles. Over 3 visits a week, you will drive a total of 12 miles per week. To find out the weekly gas consumption: divide the total miles driven by the miles per gallon. In this case, it's \( \frac{12}{20} \) gallons per week.

By calculating your gasoline consumption, you can make informed choices about when to drive and how changes in behavior, like biking or walking, can lead to savings.

Distance Conversion and Travel Efficiency

Converting distances is an essential part of calculating fuel efficiency. When determining your travel distances, ensure you're consistent with the units you're using. Here, the distance from your home to your friend’s house is measured in miles, which matches the unit for fuel efficiency (mpg).

Sometimes, depending on where you are, distance may be given in different units, such as kilometers. To keep calculations accurate, understanding how to convert these units is essential. For instance, if distance were given in kilometers, you would need to convert miles to kilometers and vice versa. Remember: 1 mile is approximately 1.60934 kilometers.

Staying consistent with units not only helps in calculating fuel efficiency accurately, it also aids in understanding the environmental and economical impacts of your travel decisions.

Environmental Impact of Reduced Gasoline Usage

Choosing to walk or bike instead of driving doesn't just save money on gas. It also benefits the environment. Cars emit greenhouse gases like carbon dioxide, which contribute to climate change. By reducing gasoline usage, you reduce the emissions released into the atmosphere.

In the example scenario, avoiding the use of your car for visits to a friend saves 3 gallons of gas over five weeks. Extend that to a year, and you're saving around 31 gallons. With each gallon of gas burned, approximately 20 pounds of CO2 is emitted. If you save 31 gallons in a year, that equates to saving approximately 620 pounds of CO2 from entering the atmosphere.

The impact of choosing cleaner transport methods contributes to healthier air quality and sets a positive example for others looking to reduce their carbon footprint.