Consider a 5 m diamter trampoline. It has an area of not quite 20 m2
If a jumper sinks 1 meter into the mat at center, the volume of the displacement cone is 6.5 m3 (1/3 base of cone times height)
Because air as to move in over the top, as well as get out from under, the air moved per jump...
Let's pay a visit to one of Schrodinger's cats.
In the classical statement of the case, we have to decide if the cat is alive or dead when the probability of the radio-active decay mechanism has a 50/50 chance of releasing the cyanide, most often posed as 60 minutes.
If I understand the MW...
Trampolines are in effect coupled springs, with the mat being the much softer spring generally.
E.g. On my Acon, when jumping about 1 meter, there is a max cone of depression about 60 cm deep and 1 meter across (1 meter point has a depression of only about 10 cm) At this same point the 160 or...
You may be overthinking this. A lot of the sorting for gravel is done with sloped screens. Given the big size difference between what you want to keep vs discard, putting it on a simple conveyer and running it down a 2" mesh grate is probably sufficient.
I think trommels are used to separate...
Just came up at a place where I was doing some trenching work for a shop line:
Owner said that code required AFCI for sub panel. Problem was that almost every motor that had brushes would set of the AFCI. True? Adjustable as to how much arc matters? He had sufficient trouble with it that...
When you freeze dry food you don't heat it. Indeed, you freeze it first, otherwise the initial evaporation/cooling leads to a crust collapse on the surface.
So you have the vacuum pump chugging away. Is this what provides the energy to allow the water to sublime?
Note to one of the comments...
Truth. The problem with extrapolating from past data is that the same data with uncertainties can fit multiple curves. The advantage of models is that they can give you a basis for 'which curve?' It's still a crap shoot.
In military strategy, you plan not for what you think the opponent will...
For some sensitive issues that have a political component in addition to a physics ones, would there be merit in creating sub-forums -- e.g. climate change as a sub-forum of Earth Sciences.
You can put the same number of lumens on the road by jacking up the lamp power before it gets filtered. This takes a rule change in max wattage for headlamps. Given the difference between tungsten and LED efficiencies, it should probably be defined in terms of illumination anyway.
I think...
One of the problems constantly cited against wind power is the lack of reliability. High altitude wind is far more predictable. Yes, to determine if it is viable you need to do comparisons to other technologies, and to the impacts on living next to a station. The good sites for wind power are...
1/2" kevlar rope has a breaking strength of 31,000 lbs and weighs 7.8 lbs/100 ft.
= 116 kg/km
So a a bit over metric ton gets you up to 10 km altitude. 2 metric tons at a 30 degree angle. Still gives you 25,000 pounds potential drag without breaking the rope.
Working strength is...
I considered this, but rejected it for drag reasons. I figured a solid sided ( from wind point of view) cylinder chimney while easy to make self supporting, would have too much drag from wind.
I also didn't realize how far synthetics had come. While not yet capable of building a beanstalk...
I've seen serious discussions of high altitude wind turbines for power generation. Right now the problem is the tether. A tether to 35,000 feet at a 30 degree angle is 70,000 feet -- 14 miles long. At present we don't have anything that can support it's own weight in 14 mile lengths.
The idea behind SO2 is that it forms a haze that reflects some sunlight. However when Pinutubu blew up, it put a fair amount of SO2 into the upper atmosphere, and indeed it did cool the Earth for a year. It also resulted in lower precipitation. Dropping the temperature but creating drought...