Before a person walks through burning coal, the person will make sure their feet are very wet. When they start walking on the coal, this moisture will evaporate and form a protective gas layer underneath the person's feet. You can see examples of this if you happen to drip some water on a hot stove or any very hot surface. The water will very easily glide around on top of a newly formed layer of air underneath it -- like air hockey pucks on an air hockey table. Note that when someone walks through burning coal, typically this is also done very quickly to prevent a great deal of exposure to possible harm. By walking quickly, thinking positively, and letting the water cushion you from immediate danger over a short distance, such a task is possible. You may have also heard of physics teachers demonstrating how this principle works by sticking their hand first in a bucket of water and then quickly in a bucket of boiling molten lead. In the lead, their hand is protected briefly by a layer of gas from the evaporated water (the water vapor). I'm fairly sure that there is a name for this particular layer of gas, but I'm afraid the name is beyond me at the moment. In other words, water vapor has a low heat capacity and poor thermal conduction. Very often, the coals or wood embers that are used in fire walking also have a low heat capacity. Sweat produced on the bottom of people's feet also helps form a protective water vapor. All of this together makes it possible, if moving quickly enough, to walk across hot coals without getting burned. WARNING: Do not attempt to perform any of the actions described above. You can seriously injure yourself. Answered by: Ted Pavlic, Electrical Engineering Undergrad Student, Ohio St. (citing my source)
The planet closest to the sun; Mercury.
So first we find the gap between the slits by the formula d=1/N
<span>N is number of lines per metre so 3700 line/cm = 370000 lines/m </span>
<span>So d=2.7*10^-6 </span>
<span>Now we use the formula dsin(angle)=n(wavelength) </span>
<span>d is the same </span>
<span>n is the order of the diffraction pattern </span>
<span>so wavelenth=dsin(angle)/n </span>
<span>=[(2.7*10^-6)*sin30]/3 </span>
<span>=4.5*10^-7 m</span>
Answer:
the object has least potential energy at mean position of the SHM
Explanation:
If a block is connected with a spring and there is no resistive force on the system
In this case the total energy of the system is always conserved and it will change from one form to another form
So here we will say that
Kinetic energy + Potential energy = Total Mechanical energy
As we can say that total energy is conserved so here we have least potential energy when the system has maximum kinetic energy
So here we also know that at mean position of the SHM the system has maximum speed and hence maximum kinetic energy.
So the object has least potential energy at mean position of the SHM
Answer:
3rd order polynomial
Explanation:
Given that the increase in the order of the polynomial the error between the curve fit and measured data will decreases hence :
The polynomial order that is best to use is the 3rd order polynomial, this is because using a 3rd order polynomial will produce a less variance and a low Bias
