If the earth is rotating at a high speed and we jump up, why doesn't the earth move below us at high speed?
Since other answers have correctly mentioned the atmosphere and such, let's take it out of the equation for the sake of argument and see what happens.In terms of the difference in the helicopter's path vs. the ground, let's look at what happens during one whole day as the Earth rotates. Assuming the helicopter can perform an ideal, vertical-acceleration-only hover, then the surface of the Earth and the helicopter have the same tangential speed as the Earth turns, due to conservation of momentum. But, since the helicopter is now a few feet (~1 meter) above the ground, the path the helicopter takes to go around the Earth during one day is now slightly longer as compared to the surface itself. The added circumference of that trip all the way around the Earth for the helicopter turns out be just 2 times Pi times the height above the ground. It takes the Earth just under 24 hours to rotate once on its axis, so the helicopter would have to move at an additional horizontal speed of maybe 18 feet (~5.5 meters) per 24 hours, or something like 0.00014 miles per hour (~0.00022 km/h) to stay directly over the same spot on the ground. This is such a negligible difference in horizontal speed that you don't notice it in any practical system.A real helicopter would deviate horizontally by a speed that is orders of magnitude more than that when it takes off anyway. And, of course, helicopters fly in the atmosphere, which is coupled to the ground. It's also fair to say that wind speed dominates any effects from conservation of momentum, as it's orders of magnitude larger, even at high altitudes. So, real aircraft worry about the difference in wind speed and direction vs. the ground, rather than orbital mechanics.
Explain why if you are standing erect the air pressure on your toes is slightly less than pressure on the nose?
Even though the altitude of the nose is higher than the elevation of the toes when standing erect and – in general, air pressure decreases with increasing elevation, the air pressure on the nose is greater than on the toes because of the their respective geometries. Considering the toe as a rectangular prism and the nose as an oblique pyramid, the surface area exposed directly to the air for the toe is a rectangle, while the surface area of the nose is a face of an oblique pyramid. Unless a person possesses an extremely large nose such as that of a T Rex, the surface of the exposed nose is less than the surface area of the exposed toe. Thus, the air pressure is greater on the nose than on the toes.
My blood pressure is 95/54. Is that too low?
No, providing you are not symptomatic it's a perfectly normal healthy variant. Of course it does depend in what situation this was taken in. If your BP is normally 140+ and all of a sudden it plummets to 95, then this may be indicative and in acute situations a plummet in BP could indicate shock etc, so 'normal' and 'good' depends on the individual in question,conditions in which it was measured and other relevant factors such as age. If this is an average reading (or there abouts) it's completely normal. Lower than average BP is only ever a problem if it's so low that it's unable to push blood around the body. Make sure you stand up slowly and keep hydrated.
Why does the lower air pressure at higher altitudes require mountain climbers to carry oxygen tanks?
Two reasons:First, if the atmospheric pressure is low enough the lungs won't be able to produce adequate suction to inhale enough air to survive. Second, oxygen is dense, gases like nitrogen will be in higher concentration than normal due to boyancy, reducing the amount of oxygen per breath. If you look at the physiology of people who live on mountains, they tend to have stronger lungs and /or are capable on function with less oxygen.
Why are water tanks always built on an elevated height?
Basically it is because the gravity creates the pressure for free, unlike pumps.We need pressurised water to flush and make taps eject water at an appropriate rate.Now, one might counter by saying that pumps will anyway be needed to collect the water at an elevated area initially. So how are we saving power ?Well, To pump water at an elevated point we need the pump to operate only till the tank is filled. That will take a limited and defined amount of time. Rather, if we don't use gravity to our aid and pump water whenever we flush, we will have to switch on the pump several times a day. This is less efficient.Hail gravity.Happy saving energy.
Very brief, sharp, localized chest pain occurring every few minutes.?
You are not qualified to decide whether or not the pains are serious. Neither is anyone here at Yahoo Answers, unless of course, they are members of the medical community. Go to a doctor ASAP to get checked out. Sharp pains occurring this much could be signs of a heart attack, stroke.
If a hole is made right through Earth so it reaches the other side, what will happen when one jumps into it?
Earth’s center of mass is pretty much at its core. It is therefore clear that the attractive force exerted by the Earth towards all bodies is directed towards its center.Why is this important? Say the particular hole looks like thisSay the center is at B (it’s not exactly B, but slightly below B). When the person is in the first leg of the journey, i.e. not yet reached the center, he is falling to the center, or basically towards the point of attraction. So, his speed naturally increases.Once he passes B, though, he is now falling away from the center, which is kind of equivalent to jumping up. The force he now experiences is against the direction of his motion, so he now decelerates. Once he completely stops, he falls back towards to the center and the entire cycle repeats.If you’ve noticed, this is basically an SHM (simple harmonic motion). He will keep oscillating about the center with a time period of about 43 minutes (if I’m not wrong).This, however, is assuming that you initially simply dropped into the hole or had low start speed. If you were actively launched into the hole at a high speed, it is possible you may not decelerate fast enough to stop within the hole. You may fly right out the other side. If the speed is high enough, you could even reach space.
Why is it that when you submerge a water bottle upside down into a tub of water, the water doesn't go into the bottle?
Air pressure.The water is trying to get up into the bottle from underneath, which means that the air inside has nowhere to go. As water tries to push into the bottle, it compresses the air, causing the air pressure to rise, which pushes back against the water.By the way, it isn't exactly true that water doesn't go into the bottle, a little bit of water gets into the mouth. And the deeper you take the bottle, the more it goes inside. If you were to take it to the bottom of a swimming pool, for example, you'd notice the water started to creep up inside the bottle. That's because there's more water pressure deeper down, and that pressure compresses the air more and more, making room for the water to get further and further inside. But, as long as the air has no way to escape, it's still going to be there, and will always take up some volume.Now, if you gave the air a way out, like poking a hole in the bottle, or running a straw or tube into it from the outside, you'd see the water level rise as it pushed the air out.