All categories

2 years ago

What is the most important thing to remember about how to calculate Mechanical Energy?

Physics

1 answer:

nataly862011 [7]2 years ago

6 0

Answer:

The mechanical energy of a classical system is simply equal to the sum of its kinetic and potential energies.

E=T+V

Where the kinetic energy T is given by the equation

T=12mv2

and the potential energy V differs depending on whatever forces are acting on the system.

If the force acting on the object is gravity (a common case) the potential energy is given by

V(r)=GMmr

where the Ms represent the mass of the two interacting objects (The system and the earth, for example), r is the distance between their centers of mass, and G is the universal gravitational constant (=6.67e-11 N m^2 kg^-2)

In simple, close to earth, situations, it takes the simpler form

V=mgh

Where m is the mass of the system, g the gravitational acceleration, and h the height.

Another well-known and important potential energy is that for a spring that obeys Hooke's law.

V(x)=12kx2

The potential energy can otherwise be calculated from its definition; the value of potential energy at a point in space is equal to the negative of the Work needed to bring the object to that point from an arbitrarily chosen reference point in space, which is generally chosen so that the potential energy will never be negative.

This is a very broad question. The most broad answer i can give is that energy (mechanical, potential, chemical, etc...) can all be measured in Joulse. This is a unit for energy. Work and energy are the same, and work is defined as force (mass * acceleration) times a distance. The base unit of force is Newtons (1kg * (9.81 meters / second^2)) and for distance it is Meters, furthermore one joule of energy is equal to one Newton-Meter. There, now we know that one joule of energy is equivalent to moving 1 kilogram of mass at 9.81 m/s^2 over a distance of 1 meter; or any such manipulation of the

It seems, that you lack knowledge of Physics and Mathematics.

Go to Ramamurti Shankar “Fundamental Physics I” on You Tube and try to follow Prof. Shankar. I know no better teacher. Just watch the videos until you have understood all the remarks and expanations. Do not learn formulas by heart; do learn the logic of how to derive those formulas. Try to understand the Principles of Physics. Do not fool yourself. Work seriously and honestly. Use your logic and try to fix your logic. (I hope that you understand what I am talking about.)

With lesson 12–15 of “Fundamental Physics I” you will get the best introduction to Special Relativity Theory. The Lorentz Transformation are just beautiful and … everything follows from them. It will take you only 5 hours if you are smart.

Have you another question ?

You might be interested in

Determine which law is appropriate for solving the following problem.

Nostrana [21]

Charles Law

Explanation:

Step 1:

It is given that the original volume of the gas is 250 ml at 300 K temperature and 1 atmosphere pressure. We need to find the volume of the same gas when the temperature is 350 K and 1 atmosphere pressure.

Step 2:

We observe that the gas pressure is the same in both the cases while the temperature is different. So we need a law that explains the volume change of a gas when temperature is changed, without any change to the pressure.

Step 3:

Charles law provides the relationship between the gas volume and temperature, at a given pressure

Step 4:

Hence we conclude that Charles law can be used.

8 0

3 years ago

Read 2 more answers

What is the purpose of a rearview mirror in a car?

Shalnov [3]

The third choice.

The driver wants to see the object that is behind him. The light reflects off the mirror into the eyes of the driver portraying the object behind him

5 0

2 years ago

Read 3 more answers

A plastic rod 1.3 m long is rubbed all over with wool, and acquires a charge of -3e-08 coulombs. we choose the center of the rod

Anestetic [448]

(a) The plastic rod has a length of L=1.3m. If we divide by 8, we get the length of each piece:
$L/8=1.3m/8=0.1625 m$

(b) The center of the rod is located at x=0. This means we have 4 pieces of the rod on the negative side of x-axis, and 4 pieces on the positive side. So, starting from x=0 and going towards positive direction, we have: piece 5, piece 6, piece 7 and piece 8. Each piece is 0.1625 m long. Therefore, the center of piece 5 is at 0.1625m/2=0.0812 m. And the center of piece 6 will be shifted by 0.1625m with respect to this:
$c_6 = 0.0812m+0.1625m=0.2437 m$

(c) The total charge is $Q=-3 \cdot 10^{-8}C$ . To get the charge on each piece, we should divide this value by 8, the number of pieces:
$Q/8=-3\cdot 10^{-8}C/8=-3.75\cdot 10^{-9}C$

(d) We have to calculate the electric field at x=0.7 generated by piece 6. The charge on piece 6 is the value calculated at point (c):
$q= -3.75\cdot 10^{-9}C$
If we approximate piece 6 as a single charge, the electric field is given by
$E=k_e \frac{q}{d^2}$
where $k_e=8.99\cdot 10^9Nm^2C^{-2}$ and d is the distance between the charge (center of piece 6, located at 0.2437m) and point a (located at x=0.7m). Therefore we have
$E= 8.99\cdot 10^9 Nm^2C^{-2} \frac{-3.75\cdot 10^9 C}{(0.2437m-0.7m)^2} =-161.9 V/m$
poiting towards the center of piece 6, since the charge is negative.

(e) missing details on this question.

5 0

3 years ago

99 POINTS

antoniya [11.8K]

Answer:

Send a pic of it so i can mark it.

Explanation:

8 0

3 years ago

Why does the large number of hydrogen atoms in the universe suggest that other elements?

lidiya [134]

Answer:

Explanation:

The abundance of the chemical elements is a measure of the occurrence of the chemical elements relative to all other elements in a given environment. Abundance is measured in one of three ways: by the mass-fraction (the same as weight fraction); by the mole-fraction (fraction of atoms by numerical count, or sometimes fraction of molecules in gases); or by the volume-fraction. Volume-fraction is a common abundance measure in mixed gases such as planetary atmospheres, and is similar in value to molecular mole-fraction for gas mixtures at relatively low densities and pressures, and ideal gas mixtures. Most abundance values in this article are given as mass-fractions.

For example, the abundance of oxygen in pure water can be measured in two ways: the mass fraction is about 89%, because that is the fraction of water's mass which is oxygen. However, the mole-fraction is about 33% because only 1 atom of 3 in water, H2O, is oxygen. As another example, looking at the mass-fraction abundance of hydrogen and helium in both the Universe as a whole and in the atmospheres of gas-giant planets such as Jupiter, it is 74% for hydrogen and 23–25% for helium; while the (atomic) mole-fraction for hydrogen is 92%, and for helium is 8%, in these environments. Changing the given environment to Jupiter's outer atmosphere, where hydrogen is diatomic while helium is not, changes the molecular mole-fraction (fraction of total gas molecules), as well as the fraction of atmosphere by volume, of hydrogen to about 86%, and of helium to 13%.[Note 1]

The abundance of chemical elements in the universe is dominated by the large amounts of hydrogen and helium which were produced in the Big Bang. Remaining elements, making up only about 2% of the universe, were largely produced by supernovae and certain red giant stars. Lithium, beryllium and boron are rare because although they are produced by nuclear fusion, they are then destroyed by other reactions in the stars.[1][2] The elements from carbon to iron are relatively more abundant in the universe because of the ease of making them in supernova nucleosynthesis. Elements of higher atomic number than iron (element 26) become progressively rarer in the universe, because they increasingly absorb stellar energy in their production. Also, elements with even atomic numbers are generally more common than their neighbors in the periodic table, due to favorable energetics of formation.

The abundance of elements in the Sun and outer planets is similar to that in the universe. Due to solar heating, the elements of Earth and the inner rocky planets of the Solar System have undergone an additional depletion of volatile hydrogen, helium, neon, nitrogen, and carbon (which volatilizes as methane). The crust, mantle, and core of the Earth show evidence of chemical segregation plus some sequestration by density. Lighter silicates of aluminum are found in the crust, with more magnesium silicate in the mantle, while metallic iron and nickel compose the core. The abundance of elements in specialized environments, such as atmospheres, or oceans, or the human body, are primarily a product of chemical interactions with the medium in which they reside.

4 0

3 years ago