Answer:
D) 21
Explanation:
When gas absorbs light , electron at lower level jumps to higher level .
and the difference of energy of orbital is equal to energy of radiation absorbed.
Here energy absorbed is equivalent to wavelength of 91.63 nm
In terms of its energy in eV , its energy content is eual to
1243.5 / 91.63 = 13.57 eV. This represents the difference the energy of orbit .
Electron is lying in lowest or first level ie n = 1.
Energy of first level
= - 13.6 / 1² = - 13.6 eV.
Energy of n th level = - 13.6 / n². Let in this level electron has been excited
Difference of energy
= 13.6 - 13.6 / n² = 13.57 ( energy of absorbed radiation)
13.6 / n² = 13.6 - 13.57 = .03
n² = 13.6 / .03 = 453
n = 21 ( approx )
Answer:
joules
joules
Explanation:
Let us convert the time in hours into seconds
Change in internal energy
where E is the internal energy in Joules
p is the power in watts
and t is the time in seconds
Joules
Amount of work done by the system
where P is the pressure and V is the volume
Substituting the given values in above equation, we get -
liter-atmospheres
Work done in Joules
Joules
Substituting the given values we get -
Thus
joules
joules
Solution :
Given data is :
Density of the milk in the tank, 
Length of the tank, x = 9 m
Height of the tank, z = 3 m
Acceleration of the tank, 
Therefore, the pressure difference between the two points is given by :
Since the tank is completely filled with milk, the vertical acceleration is 
Therefore substituting, we get
Therefore the maximum pressure difference in the tank is Δp = 47.87 kPa and is located at the bottom of the tank.
Explanation:
Echoes occur due to the reflection of sound from any obstacle, but not all the reflected sound waves lead to the phenomenon of echo. For the echo to be heard it actually depends upon the human perception as well, human ears can encounter the difference between the sound wave directly form the source and the reflected sound waves only if there is a minimum time gap of one-tenth of a second. For this time gap in the atmosphere at normal temperature and pressure the obstacle must be at least 7 meters away from the sound source.
Mechanical waves transfer energy by inducing vibrations in the propagation medium.
