Answer:
For sound waves to travel, there is a requirement of medium and density of the medium is considered to be one of the factors on which the speed of sound depends. When the medium is dense, the molecules in the medium are closely packed which means that the sound travels faster.
Explanation:
Answer:
Acid mine drainage is dissolved toxic materials wash from mines into nearby lakes and streams.
Explanation:
Acid mine drainage is the flow of acidic water with pH typically between 2 and 4, and high concentrations of other dissolved toxic materials from mines into nearby lakes and streams. It mainly occurs during metal sulfide mining, when the metal sulfide ore such as pyrite (FeS2) is exposed to water and oxygen from air to produce soluble iron and sulfuric acid.
Microorganisms, especially acidophile bacteria like Acidithiobacillus ferrooxidans grow by pyrite oxidation, i.e., oxidizing the Fe²⁺ in pyrite to Fe³⁺, which again react with pyrite and water to produce sulfuric acid. Then the acidic water flows into nearby water sources and reduces the pH value of water in those sources. As a result, heavy metals such as copper, lead, mercury, etc in other mineral ores also get dissolved into the water. The action of acidophile bacteria also increases the rate and degree of acid-mine drainage process.
The acid mine drainage causes water pollution and adversely affect the aquatic plants and animals. It also results in the contamination of drinking water, corrosion of infrastructures such as bridges, etc.
Answer:
<h2>
44 m/s</h2>
Explanation:
In this problem we are expected to calculate the velocity of Georges movements.
Given data
Total distance covered by George= 850+250= 1100 meters
Time taken by George to cover the total distance= 25 seconds
We know that velocity is, v= distance/ time
Therefore substituting our data into the expression for velocity we have
v= 1100/ 25= 44 m/s
Hence the velocity in m/s is 44
Answer:

Explanation:
We are given that a parallel- plate capacitor is charged to a potential difference V and then disconnected from the voltage source.
1 m =100 cm
Surface area =S=


We have to find the charge Q on the positive plates of the capacitor.
V=Initial voltage between plates
d=Initial distance between plates
Initial Capacitance of capacitor

Capacitance of capacitor after moving plates


Potential difference between plates after moving








Hence, the charge on positive plate of capacitor=