The Pony Express
Chapter 1
At A Nation's Crisis
The Pony Express was the first rapid transit and the first fost mail line across the continent from the Missouri River to the Pacific Coast. It was a system
by means of which messages were carried swiftly on horseback across the plains and deserts, and over the mountains of the far West It brought the
Adontic coost and the Pacific slope ten days nearer to each other.
It had a brief existence of only sixteen months and was supplanted by the transcontinental telegraph. Yet it was of the greatest importance in
binding the East and West together at a time when overland travel was slow and cumbersome, and when a great national crisis made the rapid
communication of news between these sections an imperative necessity.
The Pony Express marked the highest development in overland travel prior to the coming of the Pacific railroad, which it preceded nine years.
It, in fact, proved the feasibility of a transcontinental road and demonstrated that such a line could be built and operated continuously the year
around-a feat that had always been regarded as impossible.
The operation of the Pony Express was a supreme achievement of physical endurance on the part of man and his ever faithful companion, the
horse. The history of this organization should be a lasting monument to the physical sacrifice of man and beast in an effort to accomplish
something worthwhile. Its history should be an enduring tribute to American courage and American organizing genius.
Read this line from the Pony Express excerpt
It hod a brief existence of only sixteen months and was supplanted by the transcontinental telegraph.
Based on the corres, what does the word "supplanted" mean? (5 points)
Defeated
Joined
Replaced
Os
Oo
Unearthed
So, the time needed before you hear the splash is approximately <u>2.06 s</u>.
<h3>Introduction</h3>
Hi ! In this question, I will help you. This question uses two principles, namely the time for an object to fall freely and the time for sound to propagate through air. When moving in free fall, the time required can be calculated by the following equation:
With the following condition :
- t = interval of the time (s)
- h = height or any other displacement at vertical line (m)
- g = acceleration of the gravity (m/s²)
Meanwhile, for sound propagation (without sound reflection), time propagates is the same as the quotient of distance by time. Or it can be formulated by :
With the following condition :
- t = interval of the time (s)
- s = shift or displacement (m)
- v = velocity (m/s)
<h3>Problem Solving</h3>
We know that :
- h = height or any other displacement at vertical line = 19.6 m
- g = acceleration of the gravity = 9.8 m/s²
- v = velocity = 343 m/s
What was asked :
= ... s
Step by step :
- Find the time when the object falls freely until it hits the water. Save value as
- Find the time when the sound propagate through air. Save value as
- Find the total time
<h3>Conclusion</h3>
So, the time needed before you hear the splash is approximately 2.06 s.
Answer:
2.000.000.000
Explanation:
Apply the formula:
Work = Force . Displacement
W = 500.10 . 400.000 (the 10 come from gravity)
W = 5000 . 400.000
W = 2.000.000.000 Joules
I think it is that, can be wrong.
The statement "<span>The motion of a pendulum for which the maximum displacement from equilibrium does not change is an example of simple harmonic motion." is true.
Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions here.
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