Answer:
The roof and walls of the auditorium or cinema hall are generally covered with sound absorbent materials like draperies or compressed fibreboard to reduce reverberation. These materials reduce the formation of echoes by absorbing sound waves.
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Answer;
B. Seafloor spreading
Explanation;
-Seafloor spreading is the process by which the Earth's lithospheric plates pull apart from each other, creating gaps that are filled with magma from the asthenosphere.
-Alfred Wegener was the scientist who proposed the idea of continental drift. Wegener gave four proofs to support his continental drift hypothesis. These includes;
- Similarities in coastlines
- Fossil records are similar on separate landmasses
- Geologic evidence similarities
- Climatic Change Similarities
The process of sea floor spreading was a confirmation that Wegener's hypothesis was correct.
The options are;
a. V2 equals 2V1.
b. V2 equals (V1)/2.
c. V2 equals V1.
d. V2 equals (V1)/4.
e. V2 equals 4V1.
Answer:
Option A: V2 equals 2V1
Explanation:
Since the flow is steady, then we can say;
mass flow rate at input = mass flow rate at output.
Formula for mass flow rate is;
m' = ρVA
Thus;
At input;
m'1 = ρ1•V1•A1
At output;
m'2 = ρ2•V2•A2
So, m'1 = m'2
Now, we are told that the density of the fluid decreases to half its initial value.
Thus; ρ2 = (ρ1)/2
Since m'1 = m'2, then;
ρ1•V1•A1 = (ρ1)/2•V2•A2
Now, the pipe is uniform and thus the cross section doesn't change. Thus;
A1 = A2
We now have;
ρ1•V1•A1 = (ρ1)/2•V2•A1
A1 and ρ1 will cancel out to give;
V1 = (V2)/2
Thus, V2 = 2V1
Sediments are pieces of rock that come from other rocks that were eroded or broken by wind, water or other mechanical forces. Debris are pieces of other materials that were also swept away.
When these sediments and debris settle, they create layers. These layers are called beds. In time, several layers of other sediments and debris form on top of each other which press down onto the previous layers. Because of the pressure from the weight of the newer layers, the sediments and debris are pressed together and go through cementation. These then produce sedimentary rocks.
Metamorphic rocks form when rocks undergo heat and pressure. The heat comes from the friction resulting from the pressure. The heat can also come from radioactive decay. The rocks then slowly bake into new rocks called metamorphic rocks.
Igneous rocks form when magma and lava cool down. Magma is molten fluid found beneath the surface of the Earth. Lava is magma that has reached the surface of the Earth. When they cool down, they crystallize which make igneous rocks.
The difference between intrusive and extrusive igneous rocks is that one is made beneath the Earth and the other is made on the surface of the Earth. When magma cools, it takes a long time and the product of this cooling are intrusive igneous rocks. On the other hand, extrusive igneous rock is the result of lava cooling, which does not take as long to cool down because it occurs on the surface of the Earth.
Examples of the following types of rocks:
Sedimentary: limestone, sandstone, siltstone
Metamorphic: Marble, gneiss, slate
Igneous: Gabbro (intrusive), granite (Intrusive), obsidian (extrusive)
A bigger wave can travel longer distances, whereas a smaller one can't. This is how a wave can become as big as they can be: when a small, but mediocre wave clashes with another wave, they combine and now form a bigger wave, this process repeats until we get this big wave. Waves are created by underwater earthquakes, which could cause a tsunami or a flash flood, or they can be created by the gravitational pull of the moon.