The vibration is thermal energy ("heat" energy which every object possesses).
The second one is kinetic energy ("motion" energy of a massive object)
1. Frequency: 
The frequency of a light wave is given by:

where
is the speed of light
is the wavelength of the wave
In this problem, we have light with wavelength

Substituting into the equation, we find the frequency:

2. Period: 
The period of a wave is equal to the reciprocal of the frequency:

The frequency of this light wave is
(found in the previous exercise), so the period is:

Answer:
The coordinates of the point is (0,0.55).
Explanation:
Given that,
First charge
at origin
Second charge
Second charge at point P = (0,1)
We assume that,
The net electric field between the charges is zero at mid point.
Using formula of electric field







Hence, The coordinates of the point is (0,0.55).
The wavelength of the light beam required to turn back all the ejected electrons is 497 nm which is option (b).
- Work function is a material property defined as the minimum amount of energy required to infinitely remove electrons from the surface of a particular solid.
- The potential difference required to support all emitted electrons is called the stopping potential which is given by
.....(1) - where
is the stopping potential and e is the charge of the electron given by
.
It is given that work function (Ф) of monochromatic light is 2.50 eV.
Einstein photoelectric equation is given by:
....(2)
where K.E(max) is the maximum kinetic energy.
Substituting (1) into (2) , we get

As we know that
....(3)
where Speed of light,
and Planck's constant , 
From equation (3) , we get

Learn about more einstein photoelectric equation here:
brainly.com/question/11683155
#SPJ4
Answer:
hope this helps you're welcome