MEANING OF We never know the worth of water 'til the well is dry.?
Similar to the phrase: "You never know how much you need it till it's gone." It means that you never really appreciate the value of something until it's gone- so don't take things for granted and learn to be thankful.
What percentage of earth's water is fresh water?
1 percent, fresh drinkable without any processing. Even rain water is not drinkable, lots of pollution is in the air that is picked up by the rain.
What percentage of the earth's surface is covered in water?
The Earth is a watery place. But just how much water exists on, in, and above our planet? About 71 percent of the Earth's surface is water-covered, and the oceans hold about 96.5 percent of all Earth's water. Water also exists in the air as water vapor, in rivers and lakes, in icecaps and glaciers, in the ground as soil moisture and in aquifers, and even in you and your dog.The vast majority of water on the Earth's surface, over 96 percent, is saline water in the oceans. The freshwater resources, such as water falling from the skies and moving into streams, rivers, lakes, and groundwater, provide people with the water they need every day to live. Water sitting on the surface of the Earth is easy to visualize, and your view of the water cycle might be that rainfall fills up the rivers and lakes. But, the unseen water below our feet is critically important to life, also. How do you account for the flow in rivers after weeks without rain? In fact, how do your account for the water flowing down a driveway on a day when it didn't rain? The answer is that there is more to our water supply than just surface water, there is also plenty of water beneath our feet.Water is never sitting still. Thanks to the water cycle, our planet's water supply is constantly moving from one place to another and from one form to another. Things would get pretty stale without the water cycle!
What happens to an animal cell that is placed in distilled water?
first u need to understand osmosis... which is the movement of water from high water potential (lower concentraton of sugar lets say) to low water potential (higher concentartion of sugar) ...its like diffusion if water.. now u understand that the inside of a cell is more concentrated wth things like proteins, carbohydrates, sugar etc... so water moves into it down a concentarion gradient i.e from high water potential( low sugar concentartion-outside cell) to low water potential (high sugar concentration-inside cell) ofcourse ..its only sugar in there...so its better to use the terms high and low water potentials then say low or high concentration of something..cz there are a lot mor ethings in a cell than just sugar :) and now that the water keeps moving in..at a point the cell bursts...because an animal cell does not have cell wall (a feature available to plant cells only) it only has a cell membrane which is not very strong. this is why animal cells are bathed in special liquids :) so that the waterpotential inside cells is equal to that outside it :) they are never in pure water..that is only in the case of plant cells...beacuse they are stronger :)
What happens when a salt dissolves in water?
When you add a salt to water and the container feels cold, yes, an endothermic reaction is taking place. The solution is grabbing heat from the surroundings to get the salt to dissolve. When you add a salt to a pure solvent (say, water), the freezing point will go down and the boiling point will go up. That's because the vapor pressure of the pure solvent is lowered (this would be easier to explain with a phase diagram). Remember, the definition of BP is the temp at which the solution's vapor pressure equals the external pressure. By lowering the vapor pressure, the whole phase diagram shifts...BP to the right (higher), FP to the left (lower). You may want to check out a intro level chemistry text or at least draw out the phase diagram to see more clearly what gets lost is just words here. Did you ever try boiling water without heating it? If you have the means, hook up a vacuum to a flask of water. You don't change the vapor pressure of the water, but you reduce the external pressure enough so that the water does boil. Good question! AS
Refilling dishwasher salt?
You are doing the right thing - so many people don't bother to refill the salt but it does result in poor washing results even when using the 3in 1 tablets (the packets do state for excellent cleaning still fill up rinse aid & salt!) The container should always be full of water so you just add the salt to it and as the salt sinks down water flows out. Make sure you put the lid properly back on and then (Importantly) put the machine straight onto at least a rinse if not a short wash - reason salt water causes rusting so must be rinsed out it also will activate the water softner again. Use special dishwasher salt - never cooking or table salt as it is too fine and has additives that will choke the water softner in the machine. The salt is usually free flowing granules but my mum swears by salt tablets that some supermarkets stock as it is just a matter of throwing in a handfull of the salt tablets when required - easier than the granules, no need to use the funnel. To clarify- the dishwasher has an inbuilt water softner and the salt is required for this to be active (not to make dishes shiney as said before) Failure to refill the salt results in deposits on the dishes, cutlery and a whitish bloom - clouding on glassware called etching. Rinse aid is a wetting solution which makes the water run completely off everything so that everything dries shiney and smear free
Why is hitting water from a great height like hitting concrete?
Hitting water from a height does feel like hitting concrete, however, it does not feel like hitting concrete from the same height.As pointed out by others, any freely falling body will experience impact from the surface that it falls on / into due to conversion of PE to KE. Concrete, being solid will posses elasticity and resist deformation. Thus when a freely falling body hits, it will experience a restoring force proportional to the force it exerts on the concrete. Water, being a fluid, has elasticity replaced by viscosity which is the property by virtue of which it offers resistance to the rate of deformation rather than to deformation itself. This is what helps water provide a sort of cushioning effect to freely falling bodies. The impact felt at the water surface, while less than that experienced when falling on concrete, can still be fatal if the value exceeds 6kN. So while this would still be less than the impact felt when a body falls from the same height onto concrete, it would be enough to kill a person. And from a life and death point of view, it's the same as falling onto concrete.
What is the difference between a waterfall model and SDLC?
A software development life cycle model, or SDLC, is a structured approach to the development of software. There are a number of activities done in a sequential order to achieve the end product. Each phase is associated with a deliverable that acts as an input to the subsequent phase of SDLC.Waterfall model is one of the most popular SDLC models. It is a classic approach to software development that follows a linear and sequential method to deliver software product. This model has different deliverables from each phase. This model offers the following benefits:1. It is simple and easy to implement.2. Since the model follows a linear approach, it becomes easier to manage.3. Each phase is executed one at a time.4. This is best utilized for small-sized projects.With advantages come certain disadvantages. Some of them are discussed below:1. There is a high-risk factor involved.2. It is not beneficial for big projects.3. It cannot be used for projects where requirements can change.4. It is not suited for projects that are complex or that employ OOPS concepts.To Know More With Free Videos Visit: Waterfall Model Tutorials
What is the temperature difference of water between the top and bottom of a waterfall?
Assuming all that potential energy the water had on top turns into kinetic and finally to heat, we can say that potential energy lost = heat energy gained PE lost = mgh = mass x 10 x 400 = mass x 4000 Heat energy gained = mass x c x dT dT = temperature change heat energy gained = PE lost therefore 4000 x mass = mass x 4200 x dT (4000 x mass)/(4200 x mass) = dT = 4000/4200 = 0.95 degrees celcius temperature change = 0.95 degrees celcius
Why does'nt water fall out of the bucket when you swing it around over your head?
It's due to **CENTRIPETAL FORCE** (some others had it right, but they spelled it wrong).... here's what the experts at the Institute of Physics in London have to say on it: "The whirling bucket is the classic centripetal force experiment. Put a little water in a bucket - tie a string firmly to the bucket handle and then swing the bucket in a vertical circle. As long as the rate of rotation is great enough, the water stays in the bucket." and, here's what Glenbrook South Physics has to say on it: "The Centripetal Force and Direction Change - Any object moving in a circle (or along a circular path) experiences a centripetal force. That is, there is some physical force pushing or pulling the object towards the center of the circle. This is the centripetal force requirement. The word centripetal is merely an adjective used to describe the direction of the force. We are not introducing a new type of force, but rather describing the direction of the net force acting upon the object which moves in the circle. Whatever the object, if it moves in a circle, there is some force acting upon it to cause it to deviate from its straight-line path, accelerate inwards and move along a circular path. for example: As a bucket of water is tied to a string and spun in a circle, the tension force acting upon the bucket provides the centripetal force required for circular motion." and here's what Home Training Tools has to say about it: "It seems as if the water in the bucket is defying gravity, but is it really? No. Gravity - the force pulling down on everything - is still at work even when the bucket and water are above your head. The water's inertia wants to keep the water traveling in a straight path, but gravity is acting on the water, causing it to fall in a downward path that will eventually hit the earth. *However*, while the water is falling, the bucket is falling with it, catching the water. What keeps the bucket and water moving in a nice circular path that doesn't get wet or messy is the string. The string acts as the centripetal force that pulls the bucket and water into the center and *keeps them from following their paths of inertia*, giving the *illusion* that centrifugal force is pulling the water away from the center." links to all websites are below, with much more info. available there.