Final answer:
The usable fuel with full tanks varies based on vehicle type and fuel type. For a typical car, this could be about 84 pounds, while a full tank for an aircraft may weigh around 1874 pounds.
Step-by-step explanation:
The amount of usable fuel in full tanks can vary significantly based on the capacity of the tank and the density of the fuel being used. For instance, taking into account the reference that a typical tank might hold about 50 liters (13 gallons) of gasoline, with a density of 0.75 kg/liter, one tank has a gasoline mass of about 38 kg (approximately 84 pounds). So, if the fuel tank is full, the weight of the fuel would be around 84 pounds.
Meanwhile, for aircrafts, fuel weight can significantly be higher. A given reference suggests that if the total fuel mass is 300 gallons times 2.85 kg/gallon, the fuel would weigh about 850 kg (approximately 1874 pounds). So, a full tank of fuel for an aircraft can weigh as much as 1874 pounds. These examples indicate that the weight of usable fuel with full tanks varies considerably depending on the type and size of the vehicle or equipment.
Learn more about Fuel Weight