Answer:
httfytstuytshysts
Explanation:htrhstrhhstrsstrthrssr
<h2>
Answer: an underground lake</h2>
Explanation:
In general, sound (mechanical waves) travels faster in solids than in liquids, and faster in liquids than in gases. This is because <u>the speed of the mechanical waves is determined by a relationship between the elastic properties of the medium </u>in which they are propagated and the mass per unit volume of the medium (that is:<u>density</u>).
In other words: The speed of sound varies depending on the medium through which the sound waves travel.
So, if we are told the sound wave initially had a speed of 4,000 m/s and it suddenly decreases to 1,500 m/s, this means the sound waves passed from a solid medium to a liquid medium.
Hence, the correct option is: an underground lake.
D. Leta stetter hollingworth conducted pioneering work on <u>adolescent development and gifted children</u>.
<h3>Who is Leta stetter hollingworth?</h3>
Leta stetter hollingworth is an early feminist and active member of the Women's Suffrage Party.
Leta Stetter Hollingworth is best known for her landmark contributions to the psychology of women and to education of the gifted. That is adolescent development and gifted children.
Thus, we can conclude that Leta stetter hollingworth conducted pioneering work on <u>adolescent development and gifted children</u>.
Learn more about Leta stetter hollingworth here: brainly.com/question/2680369
#SPJ1
Velocity is computed using the formula:

Where:
V = speed
d = distance traveled
t = time/period
First you need to consider that the orbit is circular. To get the measurement or the distance going around Earth, you will need to get the circumference of the path.

Where:
C = circumference
π = 3.14
r = radius
The Earth has a radius of 6,400km, but you also need to consider that the satellite is orbiting above the surface of the Earth, so you add in the 2,000km to that radius.
r = 6,400Km + 2,000Km =
8,400Km
Next step is to insert that into our circumference formula:



The distance traveled would then be
52,778.76KmNow that we have the distance, we can then get the velocity:



The speed of the satellite is
4,398.23km/hr.