Answer:
2.9 E14 Hz
Explanation:
As we know by Einstein's equation that energy incident on the photo sensitive surface will be used by the surface to eject electron out of the surface with some kinetic energy.
This is given by
now the threshold frequency is the minimum frequency of the incident photons due to which electrons are ejected out with minimum kinetic energy or least kinetic energy.
So here when KE = 0 in the graph then corresponding to that position the frequency will be given as threshold frequency
so here from graph when KE = 0
Eye strain and self confidence issues.
Technically, this delivers a lot of energy into the Earth, but it’s
spread out over a large enough area that it doesn’t do much more than
leave footprints in a lot of gardens. A slight pulse of pressure spreads
through the North American continental crust and dissipates with little
effect. The sound of all those feet hitting the ground creates a loud,
drawn-out roar which lasts many seconds.
Answer:
cell pohnes convert sound waves into radio waves
electromagnetic waves used in cellphone communications are called: radio waves
To send out a radio signal far and wide.. it is called: broadcast
Explanation:
<h2><em>A reference point is a place or object used for comparison to determine if something is in motion. An object is in motion if it changes position relative to a reference point. You assume that the reference point is stationary, or not moving.</em></h2>
