Answer:
The temperature of star is 5473.87 K
Explanation:
Given:
Energy difference
eV
The ratio of number of particle ![\frac{N_{f} }{N_{i} } = \frac{1}{2 \times 10^{6} }](https://tex.z-dn.net/?f=%5Cfrac%7BN_%7Bf%7D%20%7D%7BN_%7Bi%7D%20%7D%20%3D%20%5Cfrac%7B1%7D%7B2%20%5Ctimes%2010%5E%7B6%7D%20%7D)
Degeneracy ratio ![\frac{g_{f} }{g_{i} } = 4](https://tex.z-dn.net/?f=%5Cfrac%7Bg_%7Bf%7D%20%7D%7Bg_%7Bi%7D%20%7D%20%20%3D%204)
From the formula of boltzmann distribution for population levels,
![\frac{N_{f} }{N_{i} } =\frac{g_{f} }{g_{i} } e^{-\frac{\Delta E}{kT} }](https://tex.z-dn.net/?f=%5Cfrac%7BN_%7Bf%7D%20%7D%7BN_%7Bi%7D%20%7D%20%3D%5Cfrac%7Bg_%7Bf%7D%20%7D%7Bg_%7Bi%7D%20%7D%20%20e%5E%7B-%5Cfrac%7B%5CDelta%20E%7D%7BkT%7D%20%7D)
Where
boltzmann constant = ![8.62 \times 10^{-5} \frac{eV}{K}](https://tex.z-dn.net/?f=8.62%20%5Ctimes%2010%5E%7B-5%7D%20%5Cfrac%7BeV%7D%7BK%7D)
![\frac{1}{2 \times 10^{6} } =4 e^{-\frac{7.5 eV}{8.62 \times 10^{-5} T} }](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%20%5Ctimes%2010%5E%7B6%7D%20%7D%20%3D4%20%20e%5E%7B-%5Cfrac%7B7.5%20eV%7D%7B8.62%20%5Ctimes%2010%5E%7B-5%7D%20T%7D%20%7D)
![8 \times 10^{6} } = e^{\frac{7.5 eV}{8.62 \times 10^{-5} T} }](https://tex.z-dn.net/?f=8%20%5Ctimes%2010%5E%7B6%7D%20%7D%20%3D%20e%5E%7B%5Cfrac%7B7.5%20eV%7D%7B8.62%20%5Ctimes%2010%5E%7B-5%7D%20T%7D%20%7D)
![\ln(8 \times 10^{6}) = {\frac{7.5 eV}{8.62 \times 10^{-5} T} }](https://tex.z-dn.net/?f=%5Cln%288%20%5Ctimes%2010%5E%7B6%7D%29%20%20%3D%20%7B%5Cfrac%7B7.5%20eV%7D%7B8.62%20%5Ctimes%2010%5E%7B-5%7D%20T%7D%20%7D)
![T = {\frac{7.5 eV}{8.62 \times 10^{-5} \ln(8 \times 10^{6})} }](https://tex.z-dn.net/?f=T%20%20%3D%20%7B%5Cfrac%7B7.5%20eV%7D%7B8.62%20%5Ctimes%2010%5E%7B-5%7D%20%5Cln%288%20%5Ctimes%2010%5E%7B6%7D%29%7D%20%7D)
K
Therefore, the temperature of star is 5473.87 K
Assuming an ideal gas, the speed of sound depends on temperature
only. Air is almost an ideal gas.
Assuming the temperature of 25°C in a "standard atmosphere", the
density of air is 1.1644 kg/m3, and the speed of sound is 346.13 m/s.
The velocity can't be specified, since the question gives no information
regarding the direction of the sound.
Explanation:
The sun's gravitational force is very strong. If it were not, a planet would move in a straight line out into space. The sun's gravity pulls the planet toward the sun, which changes the straight line of direction into a curve. This keeps the planet moving in an orbit around the sun
A ball at rest hit by a golf club has initial velocity zero. The ball will be moving after the impact at speed of 1.4 x 10⁵ m/s.
<h3>What is force?</h3>
The action of push or pull which changes the state of motion or rest of a body is called force.
The club applies a force of 700N to the ball and the time of impact is 0.05s. The mass of ball is 0.10kg.
The impact force F is equal to the change in momentum of the ball multiplied by time of impact t. The momentum is the product of mass m and velocity v after impact.
F= (mv -mu) x t
The ball is initially at rest, so u =0
F = mvt
Substitute the values into the above equation of force to find the velocity.
v = F / mt
v =700 / (0.10 x 0.05)
v = 1.4 x 10⁵ m/s
Thus, the ball will be moving after the impact at speed of 1.4 x 10⁵ m/s.
Learn more about force.
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