The tip of the fan moves through the outer side of the circle.
So it moves a distance of perimeter of circle in one revolution.
Perimeter of circle = 2
r, where r is the radius of circle.
In this case radius of circular motion = 0.19 meter
So perimeter of circle = 2
*0.19 = 0.38
= 1.194 m
So distance does the tip move in one revolution = 1.194 meter
Answer:
If the temperature of the solar surface is 5800 K then the approximate temperature of the sunspot is a) 4400 K.
Explanation:
The most straightforward way to solve this is using Stefan-Boltzmann law that states that I the energy radiated per unit surface area per unit time (watt per unit area
) of a black body is proportional to the fourth power of the temperature T of the body:
![I=\sigma T^{4}](https://tex.z-dn.net/?f=I%3D%5Csigma%20T%5E%7B4%7D)
with
being the Stefan constant.
A black body is an idealized physical body that is a perfect absorber because it absorbs all incident electromagnetic radiation and is also an ideal emitter. The Sun is considered to be a black body at different layers and different temperatures.
We are told that the intensity of a sunspot
is found to be 3 times smaller than the intensity emitted by the solar surface
, that means that:
![I_{sunspot}=\frac{I_{surface}}{3}](https://tex.z-dn.net/?f=I_%7Bsunspot%7D%3D%5Cfrac%7BI_%7Bsurface%7D%7D%7B3%7D)
then using the expression of Stefan-Boltzmann law we get that
![\sigma T_{sunspot} ^{4}=\sigma T_{surface} ^{4}](https://tex.z-dn.net/?f=%5Csigma%20T_%7Bsunspot%7D%20%5E%7B4%7D%3D%5Csigma%20T_%7Bsurface%7D%20%5E%7B4%7D)
we cross out
and use the fourth root in each side of the equation
![\sqrt[4]{T_{sunspot} ^{4}}=\frac{\sqrt[4]{T_{surface} ^{4}}}{\sqrt[4]{3}}](https://tex.z-dn.net/?f=%5Csqrt%5B4%5D%7BT_%7Bsunspot%7D%20%5E%7B4%7D%7D%3D%5Cfrac%7B%5Csqrt%5B4%5D%7BT_%7Bsurface%7D%20%5E%7B4%7D%7D%7D%7B%5Csqrt%5B4%5D%7B3%7D%7D)
![T_{sunspot}=\frac{T_{surface}}{\sqrt[4]{3} }](https://tex.z-dn.net/?f=T_%7Bsunspot%7D%3D%5Cfrac%7BT_%7Bsurface%7D%7D%7B%5Csqrt%5B4%5D%7B3%7D%20%7D)
then we use that
![T_{sunspot}=\frac{5800 K}{1,316}](https://tex.z-dn.net/?f=T_%7Bsunspot%7D%3D%5Cfrac%7B5800%20K%7D%7B1%2C316%7D)
![T_{sunspot}=4407,3 K](https://tex.z-dn.net/?f=T_%7Bsunspot%7D%3D4407%2C3%20K)
So finally we get that
![T_{sunspot}\approx4400 K](https://tex.z-dn.net/?f=T_%7Bsunspot%7D%5Capprox4400%20K)
The force exerted by the laser beam on a completely absorbing target is
.
The given parameters;
- <em>power of the laser light, P = 1050 W</em>
- <em>wavelength of the emitted light, λ = 10 μm </em>
The speed of the emitted laser light is given as;
v = 3 x 10⁸ m/s
The force exerted by the laser beam on a completely absorbing target is calculated as follows;
P = Fv
![F = \frac{P}{v} \\\\F = \frac{1050}{3\times 10^8} \\\\F = 3.5 \times 10^{-6} \ N](https://tex.z-dn.net/?f=F%20%3D%20%5Cfrac%7BP%7D%7Bv%7D%20%5C%5C%5C%5CF%20%3D%20%5Cfrac%7B1050%7D%7B3%5Ctimes%2010%5E8%7D%20%5C%5C%5C%5CF%20%3D%203.5%20%5Ctimes%2010%5E%7B-6%7D%20%5C%20N)
Thus, the force exerted by the laser beam on a completely absorbing target is
.
Learn more here:brainly.com/question/17328266
Answer:
t = 0.657 s
Explanation:
First, let's use the appropiate equations to solve this:
V = √T/u
This expression gives us a relation between speed of a disturbance and the properties of the material, in this case, the rope.
Where:
V: Speed of the disturbance
T: Tension of the rope
u: linear density of the rope.
The density of the rope can be calculated using the following expression:
u = M/L
Where:
M: mass of the rope
L: Length of the rope.
We already have the mass and length, which is the distance of the rope with the supports. Replacing the data we have:
u = 2.31 / 10.4 = 0.222 kg/m
Now, replacing in the first equation:
V = √55.7/0.222 = √250.9
V = 15.84 m/s
Finally the time can be calculated with the following expression:
V = L/t ----> t = L/V
Replacing:
t = 10.4 / 15.84
t = 0.657 s