Answer:
Explanation:
Given

mass of core
Average specific heat 
And rate of increase of temperature =
Now
P=

Thus ![\frac{\mathrm{d}T}{\mathrm{d} t}=[tex]\frac{1.60\times 10^5\times 0.3349}{150\times 10^6}](https://tex.z-dn.net/?f=%5Cfrac%7B%5Cmathrm%7Bd%7DT%7D%7B%5Cmathrm%7Bd%7D%20t%7D%3D%5Btex%5D%5Cfrac%7B1.60%5Ctimes%2010%5E5%5Ctimes%200.3349%7D%7B150%5Ctimes%2010%5E6%7D)

<h2>
Answer: B)Scientists’ understanding of cells continually improved as the results of studies built upon each other over time and formed the cell theory.</h2>
Explanation:
Nowadays we know <u>cells are essential microscopic units that make up the living beings, capable of reproducing independently. </u>
However, this is the result of a long process of discoveries and studies made since the 19th century, in which the continuous improvement of new technologies was helpful.
In fact, it is wel known the English scientist Robert Hooke was the first to discover the existence of cells by looking through a compound microscope at a cork sheet, realizing that it was made up of small polygonal holes (like those of a honeycomb) that reminded him of the chambers in which the monks stayed (called cells). Then, during the next centuries more studies were made until we had the current knowledge about the structure of a cell.
Answer:
51793 bright-dark-bright fringe shifts are observed when the mirror M2 moves through 1.7cm
Explanation:
The number of maxima appearing when the mirror M moves through distance \Delta L is given as follows,

Here,
= is the distance moved by the mirror M
is the wavelenght of the light used.
= 0.017m



Therefore, 51793 bright-dark-bright fringe shifts are observed when the mirror M2 moves through 1.7
Answer:
Spiral galaxies consist of a flat, rotating disk of stars, gas and dust, and a central concentration of stars known as the bulge. These are surrounded by a much fainter halo of stars, many of which reside in globular clusters.
Elliptical galaxies have smooth, featureless light-profiles and range in shape from nearly spherical to highly flattened, and in size from hundreds of millions to over one trillion stars. In the outer regions, many stars are grouped into globular clusters. Most elliptical galaxies are composed of older, low-mass stars, with a sparse interstellar medium and minimal star formation activity They are often chaotic in appearance, with neither a nuclear bulge nor any trace of spiral arm structure. Collectively they are thought to make up about a quarter of all galaxies.
irregular galaxies were once spiral or elliptical galaxies but were deformed by gravitational action. they are shapeless.