How much energy is needed to move an electron in a hydrogen atom from the ground state (n = 1) to n = 3?
1 answer:
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Answer:
3.26 secs
Explanation:
Diameter of sphere ( D )= 10 mm
T1 = 75°C
P = 1 atm
T∞ = 23°C
T2 = 35°c
Velocity = 10 m/s
<u>Determine how long it will take to cool the sphere to 35°C</u>
<em>Using the properties of copper and air given in the question</em>
Nu = 2 + (Re)^0.8 (Pr)^0.33
hd / k = 2 + ( vd/v )^0.8 (Pr)^0.33
∴ h ≈ 2594.7 W/m^2k
Given that :
(T2 - T∞) / ( T1 - T∞ ) = exp [ ( -hA / pv CP ) t ]
( 35 - 23 ) / ( 75 - 23 ) = exp [ - 2594.7 * 6 * t / 8933 * 387 * 10 * 10^-3 ]
= ln ( 12/52 ) = -1.466337069 = - 0.45032919 * t
∴ t ≈ 3.26 secs ( -1.466337069 / -0.45032919 )
The acceleration experienced by the particle is given by
This corresponds to the centripetal acceleration of the motion, which is related to the angular speed
of the particle and its distance r from the axis by the relationship
In our problem,
, so we can solve for :
However, we must convert it into rpm (revolution per minute).
We know that 1 rad corresponds to
revolutions, while 
. So we the conversion is
This corresponds to the centripetal acceleration of the motion, which is related to the angular speed
In our problem,
However, we must convert it into rpm (revolution per minute).
We know that 1 rad corresponds to