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myrzilka [38]
4 years ago
7

An electron is confined to a one dimensional region, bounded by an infinite potential. If the energy of the electron in its firs

t excited state is 40 meV, what is its energy in its ground state? A. 40 me V B. 80 meV C. 20 meV D. O meV E. 10 meV
Physics
1 answer:
OLga [1]4 years ago
4 0

Answer:

The energy in its ground state is 10 meV.

Explanation:

It is given that,

The energy of the electron in its first excited state is 40 meV.

Energy of the electron in any state is given by :

E=\dfrac{n^2\pi^2h^2}{8mL^2}

For ground state, n = 1

E_1=\dfrac{\pi^2h^2}{8mL^2}.............(1)

For first excited state, n = 2

40=\dfrac{2^2\pi^2h^2}{8mL^2}.............(2)

Dividing equation (1) and (2), we get :

\dfrac{E_1}{40}=\dfrac{1}{4}

E_1=10\ meV

So, the energy in its ground state is 10 meV. Hence, this is the required solution.

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Answer:

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Answer:

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The ball describes a parabolic path, and the equations of the movement are:

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Equations of the uniformly accelerated rectilinear motion of upward   (vertical ).

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Where:  

x: horizontal position in meters (m)

t : time (s)

vx: horizontal velocity  in m  

y: vertical position in meters (m)  

v₀y: initial  vertical velocity  in m/s  

vfy: final  vertical velocity  in m/s  

g: acceleration due to gravity in m/s²

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We apply Equation (3) with the known data

(vfy)² = (v₀y)² -2*g*y

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(5.7)²+ 172.48 =  (v₀y)²

v_{oy} = \sqrt{(5.7)^{2}+ 172.48 }

v₀y = 14.3 m/s

Calculation of the maximum height  the ball rise (h)

In the maximum height vfy=0

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We apply the Equation (4) :

vfy = v₀y -gt

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\alpha = tan^{-1} (\frac{-14.3 }{7.7 })

α = -61.7°

α = 61.7°, below the horizontal

i- j components of the v

v = (7.7)i + (-14.3)j in meters per second (i horizontal, j downward)

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