B Comparing two expenditures of work

[thetexan]

Let’s say we have two persons who are going to travel from Central Park in New York to the Golden Gate Bridge in San Francisco. One is going to walk and the other is going to use his skate board. And let’s say they weigh the same and take the exact same route.

the question is this...is the same amount of work done (give or take) in both cases? As I understand work, they are both moving the same mass over the same distance albeit using different methods of expenditure of effort.

Another way to ask the question...which would be the better way of travel (considering energy necessary) walk or skate board?

tex

 

[kuruman]

You need to be careful when posing questions of this kind. You say, "the question is this...is the same amount of work done (give or take) in both cases?" "Work done" is too vague. You need to specify the force doing the work. For example, if the persons are initially and finally at rest, the work done by the net force will be zero. If you want the work done by gravity, it will be $W_g=-mg\Delta h$ where $\Delta h$ is the vertical displacement of the persons. If you want the work done by air resistance, $\dots~$ it's complicated.

 

[anorlunda]

There is also a difference between physics and physiology. In physiology, a person uses energy (work) even when standing still.

So if you phrased your question using only machines, not biology, it would be clearer that you are asking about physics.

 

[JT Smith]

It's not an original question. Did you try searching the web with google or the like?

https://pubmed.ncbi.nlm.nih.gov/25085605/
"Self-selected speeds and metabolic cost of longboard skateboarding"
Eur J Appl Physiol, 2014 Nov

"...The gross metabolic cost was ~2.2 J kg(-1) m(-1) at the typical speed, greater than that reported for cycling and ~50% smaller than that of walking."