Answer:
Explanation:
<u>Simple Pendulum</u>
It's a simple device constructed with a mass (bob) tied to the end of an inextensible rope of length L and let swing back and forth at small angles. The movement is referred to as Simple Harmonic Motion (SHM).
(a) The angular frequency of the motion is computed as
We have the length of the pendulum is L=0.81 meters, then we have
(b) The total mechanical energy is computed as the sum of the kinetic energy K and the potential energy U. At its highest point, the kinetic energy is zero, so the mechanical energy is pure potential energy, which is computed as
where h is measured to the reference level (the lowest point). Please check the figure below, to see the desired height is denoted as Y. We know that
And
Solving for Y
The potential energy is
The mechanical energy is, then
(c) The maximum speed is achieved when it passes through the lowest point (the reference for h=0), so the mechanical energy becomes all kinetic energy (K). We know
Equating to the mechanical energy of the system (M)
Solving for v
We have the equation for electric field E = kQ/
Where k is a constant, Q is the charge of source and d is the distance from center.
In this case E is inversely proportional to
So, 
= 485 N/C
= 0.208 cm
= 0.620 cm
= ?
= 
= 53.20 N/C
Answer:
F = 1.047 10⁻² N
Explanation:
Let's use kinematics to find the angular acceleration
w = w₀ + α t
as for rest w₀ = 0
w = α t
α = w / t
let's reduce the magnitudes to the SI system
w = 1000 rev / min (2π rad/ 1 rev) (1 min/ 60s) = 104.72 rad / s
m = 1.00 g (1 kg / 1000 g) = 1,000 10⁻³ kg
r = 10.0 cm (1 m / 100 cm) = 0.100 m
let's calculate
α = 104.72 / 1
α = 104.72 rad / s²
angular and linear variables are related
a = α r
a = 104.72 0.100
a = 10.47 m / s²
finally we substitute in Newton's second law
F = 1 10⁻³ 10.47
F = 1.047 10⁻² N
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
