Archive for category Science
Explaining the Phenomenon of Time Dilation
Physics is an interesting subject but not necessarily easy for all students. Many times, students find it tough to understand the concepts explained to them in a classroom setting. In such cases, it is vital for the students to seek help from the private Physics tutors who can help you understand the concepts clearly. In this article, we will explain the phenomenon of time dilation.
With the introduction of the special and general theory of relativity, Albert Einstein wrecked two established orders of physics. The special theory of relativity, published in 1905, brought together space and time into a sole entity. On the other hand, in 1915, general theory of relativity showed declared the gravity to be a result of the curve of space time.
First, Albert Einstein delivered a blow to the idea of an absolute time proposed by Sir Isaac Newton. After that, he went on to find flaws with the theory of gravitation by Newton, with his own general theory of relativity. This theory states that the matter warps or bends the space time about it, and the movement of the objects is influenced by this curve.
However, it must be noted that the general and special theory of relativity are the two distinct theories. One of them describes the motion as per the inertial frames of reference, while the other describes the similarity of the accelerated frames and gravity. There is one phenomenon that is quite commonly predicted by both the theories, and it is time dilation.
The special theory mentioned above is actually based, and derived from the two very fundamental postulates, one of which states that the speed of light remains steady in vacuum and other states that the laws of physics stay the same in all sorts of inertial frame. Any frame that moves at steady velocity with deference to a fixed frame is called an inertial frame.
The principle of time dilation states that time will slowdown for space ship with reverence to the time that is related with the fixed frame. If the velocity of space ship is larger, then the time dilation will be slower. The equation brought forward for time dilation is as follows: Δt’ = Δt/ √ (1 – v2 / c2). In the formula, Δt’ refers to the time interval on the space ship, and Δt refers to the time interval for rest frame of the reference. If you want to know more about time dilation then consider hiring a Physics tutor who can explain the concepts to you with the help of practical experiments.
Are you having trouble understanding the laws of Physics? Hire a private Physics tutor now. Search for an expert private physics tutor in Houston, now.
Article Source: http://EzineArticles.com/?expert=Michael_Kightlinger
Archimedes Principle and Buoyancy
Relating buoyancy to displacement, Archimedes principle forms the basis of the relationship between solid objects and surrounding fluids. Fluids can be either a liquid or a gas, but we’ll be sticking to liquids for this article.
Archimedes principle states that any floating object displaces its own weight of fluid. In more general terms, it can also be stated as: “Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object.”
This explains why wood floats and a steel bar doesn’t. The object’s density will determine its behavior when placed in a liquid – whether it will float or sink. As a rule of thumb, if an object has a higher density than water, it will sink, if lower, it will float.
Then Why do Steel Ships Float?
Brilliant question. Steel will float only if its shape allows it to hold enough air to where its density lowers below that of water. This is why a steel bar will sink rapidly, whereas say, a steel bowl of the same mass will float. They both weigh the same amount, but the bowl holds more air within it than the bar and therefore will float due to its lower density.
In contrast, wood doesn’t have to displace as much water for it to float, as it is considerably less dense, and therefore doesn’t need as much force to keep it afloat. Both of these materials obey Archimedes principle.
Deriving an Object’s Volume from its Buoyancy
If an object is square or an otherwise “simple” geometric shape, its volume can be calculated fairly easily. But irregular shapes such as a crown for example, are more difficult. But good news! An object’s volume can be calculated by simply subtracting its mass when it’s submerged from its mass when it’s not, and multiplying by the density of water – which is one. Read the rest of this entry »