Things you always wanted to know the answer to [Vol. 3]
Discussion
SpeckledJim said:
Redmax said:
I get why running up an actual hill is harder than running on the flat, increasing potential energy and all that.
But why on earth is running on an inclined treadmill harder than running on a horizontal treadmill? Surely it's just like running but at an angle? Where's the equivalent of the potential energy you get on a real hill?
As far as your inertial frame is concerned, you are higher at the end than you were at the start.But why on earth is running on an inclined treadmill harder than running on a horizontal treadmill? Surely it's just like running but at an angle? Where's the equivalent of the potential energy you get on a real hill?
If you had stood still instead of running, you would have lost potential energy.
Surely the answer is simply that you have to raise your legs higher every pace when the running surface is inclined upwards.
Running on the spot is harder the higher you raise your knees but that's nothing to do with potential energy.
Edited by Nimby on Monday 15th May 14:20
Nimby said:
SpeckledJim said:
Redmax said:
I get why running up an actual hill is harder than running on the flat, increasing potential energy and all that.
But why on earth is running on an inclined treadmill harder than running on a horizontal treadmill? Surely it's just like running but at an angle? Where's the equivalent of the potential energy you get on a real hill?
As far as your inertial frame is concerned, you are higher at the end than you were at the start.But why on earth is running on an inclined treadmill harder than running on a horizontal treadmill? Surely it's just like running but at an angle? Where's the equivalent of the potential energy you get on a real hill?
If you had stood still instead of running, you would have lost potential energy.
Surely the answer is simply that you have to raise your legs higher every pace when the running surface is inclined upwards.
Running on the spot is harder the higher you raise your knees but that's nothing to do with potential energy.
Edited by Nimby on Monday 15th May 14:20
so goodNimby said:
SpeckledJim said:
Redmax said:
I get why running up an actual hill is harder than running on the flat, increasing potential energy and all that.
But why on earth is running on an inclined treadmill harder than running on a horizontal treadmill? Surely it's just like running but at an angle? Where's the equivalent of the potential energy you get on a real hill?
As far as your inertial frame is concerned, you are higher at the end than you were at the start.But why on earth is running on an inclined treadmill harder than running on a horizontal treadmill? Surely it's just like running but at an angle? Where's the equivalent of the potential energy you get on a real hill?
If you had stood still instead of running, you would have lost potential energy.
Surely the answer is simply that you have to raise your legs higher every pace when the running surface is inclined upwards.
Running on the spot is harder the higher you raise your knees but that's nothing to do with potential energy.
Edited by Nimby on Monday 15th May 14:20
Walking to the front of a 747 doing 500mph (so doing 503mph) is the same effort as walking to the front of a stationary 747 (so doing 3mph). And the same as walking to the rear (so doing 497 mph or -3mph.)
It's all relative to your inertial frame. Moving upwards in a stationary frame is the same as staying still in a descending frame.
Amazon and the courier guys are making a big play of delivery by drone being the future but how on earth can they keep it secure even if they can get over the airspace/urban issues ? All it takes is someone to make off with said drone and package once landed. Surely it'll cost them a fortune in thieving ?
Speed 3 said:
Amazon and the courier guys are making a big play of delivery by drone being the future but how on earth can they keep it secure even if they can get over the airspace/urban issues ? All it takes is someone to make off with said drone and package once landed. Surely it'll cost them a fortune in thieving ?
I don't think it's a real scheme. I think it's a genius bit of PR. The key message that Amazon is really innovative and quick has been transmitted (essentially for free) and whether it's true or not is for the birds.
It's great work, but not by the aeronautics department.
SpeckledJim said:
Speed 3 said:
Amazon and the courier guys are making a big play of delivery by drone being the future but how on earth can they keep it secure even if they can get over the airspace/urban issues ? All it takes is someone to make off with said drone and package once landed. Surely it'll cost them a fortune in thieving ?
I don't think it's a real scheme. I think it's a genius bit of PR. The key message that Amazon is really innovative and quick has been transmitted (essentially for free) and whether it's true or not is for the birds.
It's great work, but not by the aeronautics department.
Everyone is talking about it, and all Amazon had to do was a press release and a small video and its then all over the news rather than in traditional advert breaks!
SpeckledJim said:
I don't think it's a real scheme. I think it's a genius bit of PR.
The key message that Amazon is really innovative and quick has been transmitted (essentially for free) and whether it's true or not is for the birds.
It's great work, but not by the aeronautics department.
If it's PR, it's a very detailed campaign - they're chucking a fair bit of money at it in Cambridge: 2 sites plus personnel.The key message that Amazon is really innovative and quick has been transmitted (essentially for free) and whether it's true or not is for the birds.
It's great work, but not by the aeronautics department.
schmunk said:
SpeckledJim said:
Walking to the front of a 747 doing 500mph (so doing 503mph) is the same effort as walking to the front of a stationary 747 (so doing 3mph).
Only when you're on the inside.If you were somehow on the outside of the plane, then walking to the front of the 500mph 747 (so 503mph) would be the same effort as walking down a stationary corridor into a 500mph headwind (so doing just 3mph).
Truckosaurus said:
Speed 3 said:
Amazon ...delivery by drone .... Surely it'll cost them a fortune in thieving ?
I suspect that the solution will involve the customer having a suitable 'landing pad' that secures the package once released from the drone.ambuletz said:
I'm trying to think of a phrase/wording of something but I can't think of the exact thing. the phrase people say when they find emptiness/nothingness at the bottom of a bottle/drink (alcohol). I want to make a play on words involving that but say it with (a bottle of) chilli sauce.
I think what they and you are seeking is "oblivion", though "obliterated" is often what they get.ambuletz said:
I'm trying to think of a phrase/wording of something but I can't think of the exact thing. the phrase people say when they find emptiness/nothingness at the bottom of a bottle/drink (alcohol). I want to make a play on words involving that but say it with (a bottle of) chilli sauce.
Looking for answers in/at the bottom of a bottle?ambuletz said:
I'm trying to think of a phrase/wording of something but I can't think of the exact thing. the phrase people say when they find emptiness/nothingness at the bottom of a bottle/drink (alcohol). I want to make a play on words involving that but say it with (a bottle of) chilli sauce.
Are you writing a Best Man speech? Don't force it.How are these big concrete blocks held in place?
I walk directly underneath those blocks on a 23m tower crane every day at the moment to get to my office. My non-engineering brain is uncomfortable with the fact that there is nothing beneath them holding them in place.
On the plus side, if they did let go, I wouldn't feel a thing. Has it ever happened?
I walk directly underneath those blocks on a 23m tower crane every day at the moment to get to my office. My non-engineering brain is uncomfortable with the fact that there is nothing beneath them holding them in place.
On the plus side, if they did let go, I wouldn't feel a thing. Has it ever happened?
They have a steel reinforcement cage cast in to the blocks, with holes from front to back so they can be pinned to the hangar on the back of the crane. Or they are cast in a T shape, so that the crossbar of the T sits above two beams. Google "Crane Counterweight Kentledge" and you'll get some ideas 
ETA and they'll never fall - the crane would collapse first.
ETA and they'll never fall - the crane would collapse first.
Edited by OpulentBob on Tuesday 16th May 13:34
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