Answer:
The dominant wavelength of the sun is ![499.65nm](https://tex.z-dn.net/?f=499.65nm)
Explanation:
Wien's law is defined as:
(1)
Where
is the maximum wavelength, c is the Wien's constant and T is the temperature.
Therefore,
can be isolated from equation 1.
(2)
![\lambda_{max} = \frac{2.898x10^{-3}m\cdot K}{T}](https://tex.z-dn.net/?f=%5Clambda_%7Bmax%7D%20%3D%20%5Cfrac%7B2.898x10%5E%7B-3%7Dm%5Ccdot%20K%7D%7BT%7D)
Notice that it is necessary to express the Wien's constant in units of meters
⇒ ![2.898x10^{6} nm \cdot K](https://tex.z-dn.net/?f=2.898x10%5E%7B6%7D%20nm%20%5Ccdot%20K)
Finally, equation 2 can be used:
![\lambda_{max} = \frac{2.898x10^{6} nm \cdot K}{5800 K}](https://tex.z-dn.net/?f=%5Clambda_%7Bmax%7D%20%3D%20%5Cfrac%7B2.898x10%5E%7B6%7D%20nm%20%5Ccdot%20K%7D%7B5800%20K%7D)
![\lambda_{max} = 499.65nm](https://tex.z-dn.net/?f=%5Clambda_%7Bmax%7D%20%3D%20499.65nm)
Hence, the dominant wavelength of the sun is
Friction is caused by the uneven surfaces of touching objects
Answer:
The speed of the water shoot out of the hole is 20 m/s.
(d) is correct option.
Explanation:
Given that,
Height = 20 m
We need to calculate the velocity
Using formula Bernoulli equation
![\dfrac{1}{2}\rho v_{1}^2+\rho gh_{1}=\dfrac{1}{2}\rho v_{2}^2+\rho gh_{2}](https://tex.z-dn.net/?f=%5Cdfrac%7B1%7D%7B2%7D%5Crho%20v_%7B1%7D%5E2%2B%5Crho%20gh_%7B1%7D%3D%5Cdfrac%7B1%7D%7B2%7D%5Crho%20v_%7B2%7D%5E2%2B%5Crho%20gh_%7B2%7D)
Where,
v₁= initial velocity
v₂=final velocity
h₁=total height
h₂=height of the hole from the base
Put the value into the formula
![v_{1}^2=2g(h_{2}-h_{1})](https://tex.z-dn.net/?f=v_%7B1%7D%5E2%3D2g%28h_%7B2%7D-h_%7B1%7D%29)
![v_{1}=\sqrt{2g(h_{2}-h_{1})}](https://tex.z-dn.net/?f=v_%7B1%7D%3D%5Csqrt%7B2g%28h_%7B2%7D-h_%7B1%7D%29%7D)
![v_{1}=\sqrt{2\times9.8\times(20-0.005)}](https://tex.z-dn.net/?f=v_%7B1%7D%3D%5Csqrt%7B2%5Ctimes9.8%5Ctimes%2820-0.005%29%7D)
![v_{1}=19.7\ m/s= approximate\ 20\ m/s](https://tex.z-dn.net/?f=v_%7B1%7D%3D19.7%5C%20m%2Fs%3D%20approximate%5C%2020%5C%20m%2Fs)
Hence, The speed of the water shoot out of the hole is 20 m/s.
C.
because centripetal means that force only acts in the center of body in motion
Answer:
Approximately 18 volts when the magnetic field strength increases from
to
at a constant rate.
Explanation:
By the Faraday's Law of Induction, the EMF
that a changing magnetic flux induces in a coil is:
,
where
is the number of turns in the coil, and
is the rate of change in magnetic flux through this coil.
However, for a coil the magnetic flux
is equal to
,
where
is the magnetic field strength at the coil, and
is the area of the coil perpendicular to the magnetic field.
For this coil, the magnetic field is perpendicular to coil, so
and
. The area of this circular coil is equal to
.
doesn't change, so the rate of change in the magnetic flux
through the coil depends only on the rate of change in the magnetic field strength
. The size of the magnetic field at the instant that
will not matter as long as the rate of change in
is constant.
.
As a result,
.