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 )
Explanation:
It is given that,
The velocity of a particle is given by :
Where
v is in m/s and t is in seconds
Let a is the acceleration of the object at time t. So,
When a = 0
t = 2.5 s
a is zero at t = 2.5 s. Velocity, 
v = -75 m/s
Since, 
, s is the distance travelled
At t = 2.5 s, 
s = −83.34 m
Hence, this is the required solution.
<span>The correct answer is: Mechanical Energy
Explanation:
As the guitar strings are plunked, the potential energy stored in the strings has an ability to make them vibrate. When the strings are vibrating, that potential energy is actually converted to the kinetic energy. Hence, the whole phenomena contains both the kinetic energy and the potential energy. The sum of kinetic energy and the potential energy is called Mechanical energy. Therefore, the correct answer is Mechanical Energy.</span>
And walk another 25m west
K.e=1/2mv²
K.e=1/2 2(5)²
K.e=1/2 2×25
K.e=50/2
K.e=25J
