Answer:
a) fr = 266.92 N, fy = 1300 N, b) μ = 0.36
Explanation:
a) This is a balancing act.
Let's write the rotational equilibrium relations, where the turning point is the bottom of the ladder and the counterclockwise rotations are positive
-w x - W x₂ + R y = 0 (1)
usemso trigonometry to find distances
cos 60.08 = x / 7.5
x = 7.5 cos 60.08
x = 3.74 m
fireman
cos 60.08 = x₂ / 4
x2 = 4 cos 60
x2 = 2 m
wall support
sin 60.08 = y / 15
y = 15 are 60.08
y = 13 m
we substitute in equation 1
R y = w x + W x2
R = (w x + W x2) / y
R = (500 3.74 +800 2) / 13
R = 266.92 N
now let's write the expressions for the translational equilibrium
X axis
R -fr = 0
R = fr
fr = 266.92 N
Y Axis
Fy - w-W = 0
fy = 500 + 800
fy = 1300 N
b) ask the friction coefficient
the firefighter's distance is
cos 60.08 = x₃ / 9.00
x₃ = 9 cos 60
x₃ = 5.28 m
from equation 1
R = (w x + W x₃) / y
R = 500 3.74 + 800 5.28) / 13
R = 468.769 N
we saw that
fr = R = 468.769
The expression for the friction force is
fr = μ N
in this case the normal is the ratio to pesos
N = Fy
N = 1300 N
μ N = fr
μ = fr / N
μ = 468,769 / 1300
μ = 0.36
Explanation:
Loudness of sound is a measure of response of sound to our ear. Loudness of sound is not simply the energy reaching the human ear, but it also tells about the sensitivity of human ear detecting this energy. Loudness of sound is measured in decibel (dB). As energy reaching the ear depends on square of amplitude, loudness of sound depends on various factors namely,
(i) Amplitude of sound waves
(ii) Sensitivity of ear
(iii) Distance from the source of the sound and the listener.
The decrease in energy in the hydrogen molecule is what allows its formation on Earth, but in stars the great energy of the explosion has a kinetic energy so great that electrons cannot bind to another atom, which is why hydrogen has a single atom.
The hydrogen molecule is a form that two hydrogen atoms share their electrons decreasing the total energy of the molecule, this bond has a covalent and hydrogen bonding characteristic.
In a stellar explosion, the energy released increases the energy of the hydrogen atom, for which we have two possibilities:
- Its electron is lost, so we are in a single proton, in the case of structures where the proton and the elector are
- The hydrogen atom remains but the energy of the atom is very high so the kinetic energy of the electron prevents the electron from being shared by the other atom and the molecule cannot be formed.
When the atoms are thrown into space, the separation between them is so high that it does not allow electrons to be shared and molecules cannot be formed either.
In conclusion, the decrease in energy in the hydrogen molecule is what allows its formation on Earth, but in stars the great energy of the explosion has a kinetic energy so great that electrons cannot join another atom, which is why the hydrogen has only one atom.
Learn more about the Hydrogen atom here:
brainly.com/question/22464200
I think frequency it sounds like the correct answer but I am not completely sure if I am correct
When two surfaces slide against each other, a force called friction makes them stick very slightly together. Smooth surfaces, like ice and glass, are easy to slide over. They create very little friction. Rough surfaces like rock and sand create much more friction, and are easy to grip on to.
hope it helps...!!!
