13 Mar 2018, 02:11 PM
Your son is both right and wrong, depending on how you look at it.
The amount of useful work done is the same irrespective of the speed you travel.
However, the actual amount of energy expended does increase with speed. People move less efficiently at higher speeds and the energy expended to overcome friction (mainly air resistance) is also higher.
The amount of useful work done is the same irrespective of the speed you travel.
However, the actual amount of energy expended does increase with speed. People move less efficiently at higher speeds and the energy expended to overcome friction (mainly air resistance) is also higher.