Answer:
C
Multiple groups of scientist met at a conference to discuss the theory of continental drift
<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.
</u>
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.
Answer:
= +3,394 103 m / s
Explanation:
We will solve this problem with the concept of the moment. Let's start by defining the system that is formed by the complete rocket before and after the explosions, bone with the two stages, for this system the moment is conserved.
The data they give is the mass of the first stage m1 = 2100 kg, the mass of the second stage m2 = 1160 kg and its final velocity v2f = +5940 m / s and the speed of the rocket before the explosion vo = +4300 m / s
The moment before the explosion
p₀ = (m₁ + m₂) v₀
After the explosion
pf = m₁ + m₂ 
p₀ = [texpv_{f}[/tex]
(m₁ + m₂) v₀ = m₁ + m₂
Let's calculate the final speed (v1f) of the first stage
= ((m₁ + m₂) v₀ - m₂ ) / m₁
= ((2100 +1160) 4300 - 1160 5940) / 2100
= (14,018 10 6 - 6,890 106) / 2100
= 7,128 106/2100
= +3,394 103 m / s
come the same direction of the final stage, but more slowly
Answer:
f'=5.58kHz
Explanation:
This is an example of the Doppler effect, the formula is:
Where f is the actual frequency, 
is the observed frequency, 
is the velocity of the sound waves, 
the velocity of the observer (which is negative if the observer is moving away from the source) and 
the velocity of the source (which is negative if is moving towards the observer). For this problem:
