physics question (running vs. walking)?

Question

I remember in physics my teacher said that running and walking ended up burning the same calories according to the formula intensity = rate * time....like if you run 6 miles and it takes 20 minutes that eqals an intensity of 120.... which is the same as if you walk 4 miles and it takes 30 minutes since that equals to be an intensity of 120? I mean it seems common sense that its harder to run than walk, but then again this formula makes sense too...

Answer 1

There is some truth hidden in the mistakes. The faster you walk or run, the more calories per minute you burn. Here's a table of calories per hour as a function of how many minutes it takes you to go a mile:
30 min 245 calories/hour
20 min 324
15 min 491
10 min 981
6 min 1570

All of these work out to about 110 - 160 calories per mile. As you run faster, your metabolism does get a little less efficient, but your resting metabolism is around 65 calories per hour, so you burn that much by doing nothing.

Intensity isn't the right term to use there. The number of calories you use is calories per minute times number of minutes, or calories per mile times number of miles. The point your teacher was making is that the number of calories per mile is nearly constant.

Answer 2

allow me to give you a different perspective: there is one other factor which determines the rate of burning of calories. the metabolism rate but since you have included the factor of time you have included special relativity however minutely because distance and time form velocity or speed and through a lot of calculations whilst including the metabolism rate you burn more calories while running rather than walking but the quantity is minute. you also use more energy due to the greater demand of tissue and as the metabolism rate is different for every cell i dont think i am going to apply a differential limit on each the three trillion cells and then collectively integrate it and repeat this process just to prove that running burns more calories so just take my word on it.
another perspective that supports my theory is the work-energy thereom. as you cover more distance while running than walking yuo do more work and therefore use more energy.

Answer 3

your teacher is only correct if the 'rate' term is constant in walking and running, which it is not. your teacher is wrong.

running causes your heart to beat faster. you are burning calories much faster than when you were running. the fact is our bodies do not convert glucose to energy efficiently; alot of this energy is lost as heat, and the faster you burn calories, the less efficient the burning becomes.

to put in layman terms, burning twice as much calories does not mean you can go a certain distance twice as fast. this is why it takes much more energy to sprint a quarter mile than to crawl that distance.

Answer 4

Your teacher would be right if you didn't have air resistance, you were a perfectly efficient machine, the increase in your metabolism and calorie burn rate was perfectly linear with increase in speed, and a bunch of other non real world stuff.

Answer 5

uncomplicated physics. It takes 108 energy for somebody weighing 150lbs to flow a million mile. If it takes you quarter-hour to stroll a million mile you burn 108 energy each quarter-hour. If it takes you 6 minutes to run a million mile you burn 108 energy each 6 minutes. in case you run a million/2 a mile in 3 minutes at a fee of 108 energy each 6 minutes you burn fifty 4 energy.

Answer 6

It does make sense....but doesn't weight lose also include the heart rate at a higher level for a time ?

Answer 7

I remember something like that, however, the fact is you are walking more time than running, so its possibly correct

Answer 8

You had a great teacher.