Truck transportation has an energy cost of 0.76 kcal kg-1 km-1, and it is about 3700 km from San Francisco to Toronto.
If a romaine lettuce grown near SF has a specific energy content of 17.0 kcal (100g)-1 and the diesel-powered truck has a payload of 20,000 lbs, calculate the ratio of the amount of energy spent in transportation to the amount of energy delivered in the product.
So from what i understand i have done this but im not sure if this is correct could you please tell me what you think! thank you so much for your help =)!
20000lbs is about 9090kg.
Energy used in transport = 0.76 * 3700 * 9090 = 2.56E7 kcal
Energy in the food = 170 * 9090 = 1545300
Ratio = 2.56E7/1.55E6 = 16.5
I agree.
To calculate the ratio of the amount of energy spent in transportation to the amount of energy delivered in the product, we need to calculate the energy spent in transportation and the energy delivered in the product, and then divide the former by the latter.
First, we need to calculate the energy spent in transportation. The energy cost for truck transportation is given as 0.76 kcal kg^(-1) km^(-1), and the distance from San Francisco to Toronto is about 3700 km. So, the total energy spent in transportation is:
Energy spent in transportation = Energy cost per kg km * Distance
= 0.76 kcal kg^(-1) km^(-1) * 3700 km
Next, we need to calculate the energy delivered in the product. The romaine lettuce has a specific energy content of 17.0 kcal (100g)^(-1). The payload of the truck is given in pounds, so we need to convert it to kilograms:
Payload in kilograms = Payload in pounds / 2.20462
= 20000 lbs / 2.20462
Now, we can calculate the energy delivered in the product:
Energy delivered in the product = Energy content per 100g * Payload in kilograms
= 17.0 kcal (100g)^(-1) * Payload in kilograms
Finally, we can calculate the ratio of the amount of energy spent in transportation to the amount of energy delivered in the product:
Ratio = Energy spent in transportation / Energy delivered in the product