<h2>
Answer: U-238</h2>
Explanation:
Let's begin by explaining that for radioactive geological dating (also called radioisotope dating) in which radioactive impurities were selectively incorporated when the fossil materials were formed, it is very useful to compare it with a naturally occurring radioisotope having a known half-life.
Now, taking into account that the <u>fossils are millions and millions of years old, radioisotopes are needed that exceed this measure.
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To understand it better:
The longer the half-life of a radioisotope, the greater its utility for estimating fossil ages or geological formations.
In this sense, uranium-238 (U238) has a half-life of 4,470 million years, therefore, it is among the most commonly used radioisotopes for fossil and geological dating.
Explanation:
Suspension bridges, like the Golden Gate Bridge or the Brooklyn Bridge, use tension force as the primary source of force that cables use to hold their spans up. The supporting cables receive the tension forces of the bridge, and this same force passes to the anchorages and into the ground
Answer:
25 m/s
Explanation:
First of all, we can find the acceleration the object by using Newton's second law of motion:
where
F = 20.0 N is the net force applied on the object
m = 4.0 kg is the mass of the object
a is its acceleration
Solving for a, we find
Now we know that the motion of the object is a uniformly accelerated motion, so we can find its final velocity by using the following suvat equation:
where
v is the final velocity
u = 0 is the initial velocity
is the acceleration
t = 5 s is the time
By substituting,
Answer:<span>Humid air is lighter, so it has lower pressure.
The reason is the molecules of water are H2O, whose molar mass is 18 g/mol.
These molecules displaces molecules of N2 and O2, whose molar masses are:
N2: 2*14g/mol = 28 g/mol, and
O2: 2*16g/mol = 32 g/mol.
Then molecules of 28g/mol and 32 g/mol are being replaced with molecules of 18g/mol, leading to a lower weight of the same volume of air, which results in lower pressure.
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