Things you always wanted to know the answer to [Vol. 3]

[RobinOakapple]

Hmmm, not what I expected. Seems to me that all the person staying in one place has to do is to move his legs sufficiently to maintain position, whereas the person climbing is actually raising his whole body weight to a higher level.

[walm]

RobinOakapple said:

Hmmm, not what I expected. Seems to me that all the person staying in one place has to do is to move his legs sufficiently to maintain position, whereas the person climbing is actually raising his whole body weight to a higher level.

If he is stepping like a normal person then it is a fairly rapid step.
So, the amount the step drops AS he makes the step is pretty small.
(Although it would be a far bigger effect than gravity or air resistance in fairness.)

So you are right it is lower for the staying in place guy but not by much.

[RobinOakapple]

walm said:

If he is stepping like a normal person then it is a fairly rapid step.
So, the amount the step drops AS he makes the step is pretty small.
(Although it would be a far bigger effect than gravity or air resistance in fairness.)

So you are right it is lower for the staying in place guy but not by much.

I can't see that the speed makes any difference, but whatever the speed of the climbing person is, that's the speed of the escalator. It seems to me (I say seems as I don't have an escalator to experiment on, and only a fairly basic knowledge of physics) that the upper body of the person on the down escalator is remaining relatively motionless as the right foot takes over gradually while the left foot is still taking the weight of the person. So the legs only have to deal with their own weight and not the weight of the rest of the body.

If I've got this right so far then the energy required is going to be less that half of that required for climbing. Not sure though, hence the question.

[Europa1]

What's Kelly Osborne for?

[silverthorn2151]

RobinOakapple said:

Hmmm, not what I expected. Seems to me that all the person staying in one place has to do is to move his legs sufficiently to maintain position, whereas the person climbing is actually raising his whole body weight to a higher level.

If I am stationery on an escalator going down I promise you it takes less energy that walking up any sort of escalator. Come to think of it, less than walking down as well.

You guys obviously don't use the tube much.

[walm]

silverthorn2151 said:

If I am stationery on an escalator going down I promise you it takes less energy that walking up any sort of escalator.

He is asking about stationary relative to the ground. Not standing still and going down as the escalator goes down.

[walm]

RobinOakapple said:

I can't see that the speed makes any difference, but whatever the speed of the climbing person is, that's the speed of the escalator.

When people walk up stairs it isn't a completely smooth consistent speed with the upper body rising at a steady pace though.
It's kind of jerky.
The step-up process is fast, then a pause, then the next step.

So, if the actual stepping speed is very fast the distance that the step you are stepping onto drops while you step onto it, is small.
And hence the distance you rise is very similar to the distance you rise on a regular set of stairs of the same dimensions.

If the guy trying to stay stationary changed the way he moved such that his upper body was totally static as you describe then it would be much less, yes.
But that isn't how people normally climb stairs!

[Halmyre]

RobinOakapple said:

Does walking up a stationary escalator require more energy than staying in the same place on an escalator that is going down (assuming that the escalator in the second part is running at the same speed as the person is the first part)?

I think I know the answer, but there will be a follow up question.

...and will he take off?

[98elise]

RobinOakapple said:

Does walking up a stationary escalator require more energy than staying in the same place on an escalator that is going down (assuming that the escalator in the second part is running at the same speed as the person is the first part)?

I think I know the answer, but there will be a follow up question.

I would say you are using more enery on the stationary escalator as you will weigh very slightly less when the step is moving down (f=ma)

I have some evidence of this. I'm ex RN and when a ship is in rough sea climbing steps is significantly easier when the ship is decending a big wave. The faster the fall the lighter you feel. Its a wierd sensation as your frame of reference is unchanged.

[Europa1]

silverthorn2151 said:

If I am stationery on an escalator going down I promise you it takes less energy that walking up any sort of escalator. Come to think of it, less than walking down as well.

You guys obviously don't use the tube much.

Surely the effort you use is dependent on what kind of stationery you are being on the escalator?

[matchmaker]

RenesisEvo said:

'Wild Rice'. From a supermarket. Ingredients clearly state it's only 15% wild rice.

I'm quite certain there are many things in life that can't be advertised as being something, if they are only 15% that thing. A pork sausage that's just 15% pork?

So how does that work? And why isn't it 20%, 50%, 75% - or 100%?

Like Richmond "sausages"? How a pink tube of sludge can be described as a sausage is beyond me.

[popeyewhite]

98elise said:

RobinOakapple said:

Does walking up a stationary escalator require more energy than staying in the same place on an escalator that is going down (assuming that the escalator in the second part is running at the same speed as the person is the first part)?

I think I know the answer, but there will be a follow up question.

I would say you are using more enery on the stationary escalator as you will weigh very slightly less when the step is moving down (f=ma)

I have some evidence of this. I'm ex RN and when a ship is in rough sea climbing steps is significantly easier when the ship is decending a big wave. The faster the fall the lighter you feel. Its a wierd sensation as your frame of reference is unchanged.

Nearly the same discussion as running on a treadmill vs running outdoors. The treadmill is slightly easier due to less wind resistance. The biomechanics of the leg movements are slightly different as well.

[singlecoil]

popeyewhite said:

98elise said:

RobinOakapple said:

Does walking up a stationary escalator require more energy than staying in the same place on an escalator that is going down (assuming that the escalator in the second part is running at the same speed as the person is the first part)?

I think I know the answer, but there will be a follow up question.

I would say you are using more enery on the stationary escalator as you will weigh very slightly less when the step is moving down (f=ma)

I have some evidence of this. I'm ex RN and when a ship is in rough sea climbing steps is significantly easier when the ship is decending a big wave. The faster the fall the lighter you feel. Its a wierd sensation as your frame of reference is unchanged.

Nearly the same discussion as running on a treadmill vs running outdoors. The treadmill is slightly easier due to less wind resistance. The biomechanics of the leg movements are slightly different as well.

I don't think it is, as neither of those involves an uphill climb. If the run was uphill and the treadmill sloped to the same degree, then the uphill runner would use quite a bit more energy.

[silverthorn2151]

Europa1 said:

silverthorn2151 said:

If I am stationery on an escalator going down I promise you it takes less energy that walking up any sort of escalator. Come to think of it, less than walking down as well.

You guys obviously don't use the tube much.

Surely the effort you use is dependent on what kind of stationery you are being on the escalator?

I am being the type of stationery that can't spel for tofee.

[silverthorn2151]

walm said:

silverthorn2151 said:

If I am stationery on an escalator going down I promise you it takes less energy that walking up any sort of escalator.

He is asking about stationary relative to the ground. Not standing still and going down as the escalator goes down.

[popeyewhite]

singlecoil said:

I don't think it is, as neither of those involves an uphill climb. If the run was uphill and the treadmill sloped to the same degree, then the uphill runner would use quite a bit more energy.

Hold on - gravity, bodyweight and muscles used are identical - so why "quite a bit more energy"?

N.B. I used 'nearly' in my primary post.

[walm]

silverthorn2151 said:

Dammit!

[singlecoil]

popeyewhite said:

singlecoil said:

I don't think it is, as neither of those involves an uphill climb. If the run was uphill and the treadmill sloped to the same degree, then the uphill runner would use quite a bit more energy.

Hold on - gravity, bodyweight and muscles used are identical - so why "quite a bit more energy"?

N.B. I used 'nearly' in my primary post.

As RO said in one of his later posts on this thread, the chap on the stationary elevator is lifting his entire body weight, but the one on the down elevator is only having to lift his legs. Big difference.

[popeyewhite]

singlecoil said:

popeyewhite said:

singlecoil said:

I don't think it is, as neither of those involves an uphill climb. If the run was uphill and the treadmill sloped to the same degree, then the uphill runner would use quite a bit more energy.

Hold on - gravity, bodyweight and muscles used are identical - so why "quite a bit more energy"?

N.B. I used 'nearly' in my primary post.

As RO said in one of his later posts on this thread, the chap on the stationary elevator is lifting his entire body weight, but the one on the down elevator is only having to lift his legs. Big difference.

I think RO may be wrong. In both instances the leg muscles push the bodyweight upwards.

[singlecoil]

popeyewhite said:

singlecoil said:

popeyewhite said:

singlecoil said:

I don't think it is, as neither of those involves an uphill climb. If the run was uphill and the treadmill sloped to the same degree, then the uphill runner would use quite a bit more energy.

Hold on - gravity, bodyweight and muscles used are identical - so why "quite a bit more energy"?

N.B. I used 'nearly' in my primary post.

As RO said in one of his later posts on this thread, the chap on the stationary elevator is lifting his entire body weight, but the one on the down elevator is only having to lift his legs. Big difference.

I think RO may be wrong. In both instances the leg muscles push the bodyweight upwards.

But the body of the chap on the moving escalator is mostly staying in one place, it's not going uphill. So he's not lifting his body weight, he's only lifting his legs.