Answer:
N = 3032 turns
Explanation:
The magnetic field produced by a solenoid is described by
B = μ₀ n I
Where is the permittivity in a vacuum with a value of 4π 10⁻⁷ N /A², n is the turn density and I the current
Let's apply this equation to the problem, the turn density is the number of turns per unit length, in this case it is the same magnet length
L = 8 cm = 0.08 m
Let's calculate
B = μ₀ N/L I
N = B L / μ₀ I
N = 0.10 0.08 / (4π 10⁻⁷ 2.1)
N = 3,032 103 turns
The concepts necessary to solve this problem are framed in the expression of string vibration frequency as well as the expression of the number of beats per second conditioned at two frequencies.
Mathematically, the frequency of the vibration of a string can be expressed as

Where,
L = Vibrating length string
T = Tension in the string
Linear mass density
At the same time we have the expression for the number of beats described as

Where
= First frequency
= Second frequency
From the previously given data we can directly observe that the frequency is directly proportional to the root of the mechanical Tension:

If we analyze carefully we can realize that when there is an increase in the frequency ratio on the tight string it increases. Therefore, the beats will be constituted under two waves; one from the first string and the second as a residue of the tight wave, as well


Replacing
for n and 202Hz for 



The frequency of the tightened is 205Hz
Answer:
ΔP.E = 6.48 x 10⁸ J
Explanation:
First we need to calculate the acceleration due to gravity on the surface of moon:
g = GM/R²
where,
g = acceleration due to gravity on the surface of moon = ?
G = Universal Gravitational Constant = 6.67 x 10⁻¹¹ N.m²/kg²
M = Mass of moon = 7.36 x 10²² kg
R = Radius of Moon = 1740 km = 1.74 x 10⁶ m
Therefore,
g = (6.67 x 10⁻¹¹ N.m²/kg²)(7.36 x 10²² kg)/(1.74 x 10⁶ m)²
g = 2.82 m/s²
now the change in gravitational potential energy of rocket is calculated by:
ΔP.E = mgΔh
where,
ΔP.E = Change in Gravitational Potential Energy = ?
m = mass of rocket = 1090 kg
Δh = altitude = 211 km = 2.11 x 10⁵ m
Therefore,
ΔP.E = (1090 kg)(2.82 m/s²)(2.11 x 10⁵ m)
<u>ΔP.E = 6.48 x 10⁸ J</u>
Answer:
A measurement standard is a quantity that people agree to use as a comparison. Standards are important because they allow measurements to be compared even if different people in different parts of the world take them.
Hope this helps ⊂◉‿◉つ