Answer:

Explanation:
h = Planck's constant = 
c = Speed of light = 
E = Energy = 
Wavelength ejected is given by

The maximum wavelength in angstroms of the radiation that will eject electrons from the metal is 
1 because the the mid night summer is dark
Explanation:
A simple way to state Newton's first law is:
For every action force, there is a reaction force which is equal in magnitude and opposite in direction.
Frequency is inversely proportional to wavelength.
Wavelength is the spacial period, and more generally the frequency is inversely proportional to the period.
If the wave's speed if c, then f=c/l where l is the wavelength.
That could be an electromagnet,
and it could also be an solenoid.