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
The correct answer to the question above is Thermal Energy. As you heat a steak on a grill, the kind of energy that you are increasing is Thermal Energy. Thermal energy is the energy that come from heat, since you are you grilling the steak which means there is fire underneath, it has thermal energy.
Answer: D. 0.29 m
Explanation:
We will use the following equations to describe the leap of the cat:
(1)
(2)
Where:
is the height of the cat
is the cat's initial velocity
is the acceleration due gravity
is the time
is the y-component of the velocity
Now the cat will have its maximum height 
when 
. So equation (2) is rewritten as:
(3)
Finding :
(4)
(5)
(6)
Substituting (6) in (1):
(7)
Finally:
(8)
Answer:
The spring constant is 215.6 N/m.
Explanation:
Given that,
Distance = 39 cm
Compresses length = 29 cm
Mass = 2.2 kg
We need to calculate the distance
Using formula of distance
Put the value into the formula
We need to calculate the spring constant
Using formula of restoring force
Where, F = force
x = distance
Put the value into the formula
Hence, The spring constant is 215.6 N/m.
