Question

Considering that a food calorie is equal to about 4 kJ of energy, you wonder how the amount of energy in a serving size of your favorite food compares in other situations. For example, how does this compare to the amount of energy that’s necessary to lift a fully-loaded pickup truck up three meters above the ground? Let’s say the truck has a mass of 2500 kg.

Answer 1

Answer with Explanation:

We are given that

One food calorie=4KJ=
`4* 1000=4000J`

1kJ=1000 J

Height,h=3 m

Mass,m=2500 kg

Energy required to lift the truck=
`mgh`

Where
`g=9.8m/s^2`

Using the formula

Energy required to lift the truck=
`2500* 3* 9.8`

Energy required to lift the truck=73500J=
`(73500)/(1000)=7.35KJ`

If a food item gives 20 food calorie

Then, the energy obtained from food=
`20* 4=80KJ`

Which is greater than the energy required to lift the truck.