No one answeres physic questions, iveneeded help all morning
Which were difficulties that the builders of the transcontinental railroad found ways to overcome? Select all the choices that apply.
Answer: Out of all the options presented above the ones that represent the difficulties that the builders of the transcontinental railroad found ways to overcome are answer choices A) providing supplies to build the tracks and support the workers and B) natural barriers such as mountains, rivers, and forests. It was also the same reason why the transcontinental railroad was being constructed. It would help the transportation of if this is hitory i dont know what subject this is but if its history heres the answers
Answer:
d. The length of the string is equal to one-half of a wavelength
Explanation:
A stretched string of length L, fixed at both ends, is vibrating in its third harmonic. How far from the end of the string can the blade of a screwdriver be placed against the string without disturbing the amplitude of the vibration
a. The length of the sting is equal to one-quarter of a wavelength.b. The length of the string is equal to the wavelength.c. The length of the string is equal to twice the wavelength.d. The length of the string is equal to one-half of a wavelength
e. The length of the string is equal to four times the wavelength
A stretched string of length L fixed at both ends is vibrating in its third harmonic H
How far from the end of the string can the blade of a screwdriver be placed against the string without disturbing the amplitude of the vibration
d. The length of the string is equal to one-half of a wavelength
There are two points during vibration , the node and the antinode
the node is the point where the amplitude is zero.
from the third harmonics, there are two nodes. The first node is half of the wavelength which is the closest to the fixed point.
for third harmonics=3/2lamda
Answer:
L = 0.44 [m]
Explanation:
Here we can use the Lorentz transformation related to length to solve it:

<u>Where</u>:
L₀ is the length of the moving reference frame (penguin #1)
L is the length of the fixed reference frame (penguin #2)
β is the ratio between v and c
<u>We know that v = 0.9c so we can find β.</u>

![L=1 [m]\sqrt {1-0.9^{2}} = 0.44 [m]](https://tex.z-dn.net/?f=L%3D1%20%5Bm%5D%5Csqrt%20%7B1-0.9%5E%7B2%7D%7D%20%3D%200.44%20%5Bm%5D%20)
Therefore, the length of the meter stick of #1 observed by #2 is 0.44 m.
I hope it helps you!
The answer is C. Gravity would pull too hard on the atmosphere.