Who Did More Work?

[arakboss]

Two people each walked 3 miles at a pace of 3 miles per hour. One of the persons weighed 260lbs the other person weighed 130lbs. Which person did more work?

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[Provincial]

Uphill?

 

[arakboss]

Uphill?

Flat.

 

[Andy54Hawken]

Depends on if one is named Igor....
Andy

 

[MannyGlocks]

Is this a riddle like: Which one is heaviest - A pound of feathers or a pound of lead?

Oh, I suck at riddles...

 

[MTpockets]

If they carried nothing... Neither performed work.
If they carried a memorized message... Neither performed work.
If they both carried a Post-It note the three miles... They preformed the same amount of work.
If they took equal turns carrying each other... The lighter person performed more work.
If they both walked three miles to the solent green facility to be processed... The heavier person performed the most work.

If they didn't punch the clock... They won't get paid for their work.

Edit to add

 

[TTSX]

If two trains left the station 5 minutes apart travelling in opposite directions at half the speed of smell, when will my nachos be ready?

 

[CamoDeafie]

Well. The heavier person puts more stress, and possibly their muscles did more work to move the weight 3 miles. So, the heavier person burned more calories than the lighter person for the same distance at the same pace. but the lighter person may well just jog the 3 miles and burn the same amount of calories.

 

[arakboss]

Well. The heavier person puts more stress, and possibly their muscles did more work to move the weight 3 miles. So, the heavier person burned more calories than the lighter person for the same distance at the same pace. but the lighter person may well just jog the 3 miles and burn the same amount of calories.

Bingo! Not everybody sees it that way.

 

[TTSX]

Bingo! Not everybody sees it that way.

Who? Who doesn't see it that way? More weight over the same distance in the same period of time takes more energy/effort to accomplish. That's middle school stuff.

 

[monkeybutler]

Bingo! Not everybody sees it that way.

Seems screechingly obvious.

The fat guy has to do more work given all other factors being equal.

 

[Andy54Hawken]

Who did more work while walking....?
Not me...I'm so lazy , I don't even sleep walk...
Andy

 

[MTpockets]

Let's get Physics'ical.


If a large dozer pushes a 5 cubic yards of gravel a distance 25 feet, and then a small dozer moves the 5 cubic yards of gravel back to the original position....
...the same amount of work was accomplished. The size of the vehicle, nor amount of fuel used, is factored into the work.

Maybe the original question was relating to thermal transfer?

 

[TTSX]

Let's get Physics'ical.
View attachment 1811750

If a large dozer pushes a 5 cubic yards of gravel a distance 25 feet, and then a small dozer moves the 5 cubic yards of gravel back to the original position....
...the same amount of work was accomplished. The size of the vehicle, nor amount of fuel used, is factored into the work.

Maybe the original question was relating to thermal transfer?

In your analogy, the large dozer should be moving 10 cubic yards of gravel while the small moves 5.

 

[CamoDeafie]

Let's get Physics'ical.
View attachment 1811752

If a large dozer pushes a 5 cubic yards of gravel a distance 25 feet, and then a small dozer moves the 5 cubic yards of gravel back to the original position....
...the same amount of work was accomplished. The size of the vehicle, nor amount of fuel used, is factored into the work.

Maybe the original question was relating to thermal transfer?

It might have been more of...

Did both persons, walking same pace, for the same distance, burn the same amount of calories, if one person is twice as large as the other person?

Edit a better analogy. Stick two identical 200hp engines and identical transmissions in two vehicles, one is a 2,000lb car, the other a 4,000lb van.. which engine burned more fuel to go the same distance?

 

[MTpockets]

In your analogy, the large dozer should be moving 10 cubic yards of gravel while the small moves 5.

The operator of the large dozer noticed the pyrometer was indicating a higher than normal exhaust temperature, so he was using half throttle while pushing 5 cubic yards of gravel.

It might have been more of...

Did both persons, walking same pace, for the same distance, burn the same amount of calories, if one person is twice as large as the other person?

Edit a better analogy. Stick two identical 200hp engines and identical transmissions in two vehicles, one is a 2,000lb car, the other a 4,000lb van.. which engine burned more fuel to go the same distance?

If burning fuel is the purpose, then it would be considered work.
The type of work you are describing would include a purpose, an activity and a result. (Original Posted Question had no described Purpose)

Edit to add: In the OP, if the purpose was to reach the end of the 3 miles. The participants performed the same amount of work.

 

[albin25]

Both did the same amount of work…
…. The fat one just burned more energy to do it.

 

[arakboss]

I anticipated the mixed answers on the first question. Here is the second question.


Two people, each weighing 130lbs walked 3 miles at a pace of 3 miles per hour. One person carried a backpack weighing 100lbs. The other person carried a backpack weighing 30lbs. Which person did more work?

 

[lucusloc]

State your assumptions; are we talking work in the physics sense or work in the practical sense? Your assumptions define the answer.

In the physics sense the weight of the gravel and the wight of the dozer counts (or in the original question the weight of the person). So a bigger dozer does more work since it is moving more mass (weigh of dozer + weight of gravel) and similarly the bigger person is doing more work to move the mass of their body.

However in a practical sense we only care about the gravel, not the device being used to push it. We divide up the problem into work and efficiency. The gravel defines the amount of work that is done (the same in both cases) while the machine used to move it defines the efficiency that it gets done with (in one or some of many dimensions; fuel consumption, time taken, total cost to do the job, etc.). In that sense the two people walking did the same amount of work (they went to the same destination in the same amount of time).

If you do not define the parameters of your problem then you leave it open to interpretation, and then there is no right answer. If you claim there is then the game we are playing is not actually "what is the correct answer" it is "guess what assumptions I made that allows me to conclude my answer is correct."

Problem space definition is a key aspect of problem solving. If you cannot narrowly define your specifications then any number of conclusions are possible. If you need a specific answer then you need a specific problem space. The more specific the answer needs to be the more specific the problem definition needs to be.

 

[arakboss]

State your assumptions; are we talking work in the physics sense or work in the practical sense? Your assumptions define the answer.

In the physics sense the weight of the gravel and the wight of the dozer counts (or in the original question the weight of the person). So a bigger dozer does more work since it is moving more mass (weigh of dozer + weight of gravel) and similarly the bigger person is doing more work to move the mass of their body.

However in a practical sense we only care about the gravel, not the device being used to push it. We divide up the problem into work and efficiency. The gravel defines the amount of work that is done (the same in both cases) while the machine used to move it defines the efficiency that it gets done with (in one or some of many dimensions; fuel consumption, time taken, total cost to do the job, etc.). In that sense the two people walking did the same amount of work (they went to the same destination in the same amount of time).

If you do not define the parameters of your problem then you leave it open to interpretation, and then there is no right answer. If you claim there is then the game we are playing is not actually "what is the correct answer" it is "guess what assumptions I made that allows me to conclude my answer is correct."

Problem space definition is a key aspect of problem solving. If you cannot narrowly define your specifications then any number of conclusions are possible. If you need a specific answer then you need a specific problem space. The more specific the answer needs to be the more specific the problem definition needs to be.

Work = Mass moved a given distance.