I completely do not understand how to do them, can somebody explain it and give me the answer please :)
1. In Europe, gasoline efficiency is measured in km/L. If your car's gas mileage is 40.0 mi/gal, how many liters of gasoline would you need to buy to complete a 142-km trip in Europe? Use the following conversions:1km = .6214mi and 1 gal = 3.78L.
2. While in Europe, if you drive 103km per day, how much money would you spend on gas in one week if gas costs 1.10 euros per liter and your car's gas mileage is 39.0 mi/gal ? Assume that 1 euro = 1.26 $
3. A sprinter set a high school record in track and field, running 200.0 m in 21.9 seconds. What is the average speed of the sprinter in kilometers per hour?
1. In Europe, gasoline efficiency is measured in km/L. If your car's gas mileage is 40.0 mi/gal, how many liters of gasoline would you need to buy to complete a 142-km trip in Europe? Use the following conversions:1km = .6214mi and 1 gal = 3.78L.
2. While in Europe, if you drive 103km per day, how much money would you spend on gas in one week if gas costs 1.10 euros per liter and your car's gas mileage is 39.0 mi/gal ? Assume that 1 euro = 1.26 $
3. A sprinter set a high school record in track and field, running 200.0 m in 21.9 seconds. What is the average speed of the sprinter in kilometers per hour?
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1:
40.0mi/gal * (1km/.6214mi)=64.371km/g
65.371km/g * (1gal/3.78L) = 17.03 km/L
Use the units to guide your work. Look at what the answer needs to be in (km/L) and figure and use your conversions. Your conversions are ratios and can be used either as 1km/.6214mi or .6214mi/1km. You want to have the old units (mi) cancel and you want to be left with in this case km. So use the ratio that will accomplish this.
17.03km/L *#liters =142 km
#liters= 8.3
again look at the units."How many liters?" the final unit needs to be in liters. So you must get rid of the km in the 17.03km/L. So 142km /(17.03km/L) ==> 142km * (L/17.03km) the km cancel and you are left with km in the numerator.
40.0mi/gal * (1km/.6214mi)=64.371km/g
65.371km/g * (1gal/3.78L) = 17.03 km/L
Use the units to guide your work. Look at what the answer needs to be in (km/L) and figure and use your conversions. Your conversions are ratios and can be used either as 1km/.6214mi or .6214mi/1km. You want to have the old units (mi) cancel and you want to be left with in this case km. So use the ratio that will accomplish this.
17.03km/L *#liters =142 km
#liters= 8.3
again look at the units."How many liters?" the final unit needs to be in liters. So you must get rid of the km in the 17.03km/L. So 142km /(17.03km/L) ==> 142km * (L/17.03km) the km cancel and you are left with km in the numerator.