<span>C is the correct answer. Electron microscopes require a vacuum to work, so living cells cannot be seen because they cannot respire. Light microscopes use a ray of visible light instead of a beam of electrons to magnify something so it can be seen by the naked eye. There are two different types of electron microscope: transmission (TEM) and scanning (SEM).</span>
Average speed = (total distance covered) / (time to cover the distance)
Total distance = (80m) + (125m) + (45m) = 250 meters
Overall time = 10 minutes
Average speed = (250 meters) / (10 minutes)
<em>Average speed = 25 meters/minute </em>
Since we're only looking for average speed and not velocity, we don't care about any of the directions, and we don't need to calculate Mary's displacement.
Bohr explained that the electron revolve around a orbit of fixed energy level that Rutherford fails to explain !!!
Answer:
Option (D)
Explanation:
Weathering refers to the disintegration of rocks due to the different geological processes that are initiated by agents such as wind, water and ice.
In a region where the temperature is high, and there is sufficient amount of moisture content in the air, there occurs high rate of physical, chemical and biological type of weathering.
- Physical weathering processes such as freeze-thaw method and exfoliation method commonly occurs in this type of region.
- Chemical weathering processes such as hydrolysis, oxidation, as well as carbonation method occurs in the region of high temperature, moist climatic condition.
- Biological weathering also is possible up to some extent as the plants takes up water from the rainfall and also receive enough sunlight for its growth, as a result of which it leads to the breakdown of rocks.
Thus, the correct answer is option (D).
Answer:
The second engine with no cars will accelerate more.
Explanation:
Since the engines are identical so they hacve the same mass. The first engine has 10 cars attached which adds more mass to it whereas second engine has no cars attached.
Therefore second engine is lighter in mass than the first one.
<u>We know from the Newton's second law of motion:</u>


Now, according to question both the engines exert same force for moving.
We see that :

So more is the mass, lesser is the acceleration, hence the second engine with no cars will accelerate more.