The power of the laser is

by using the relationship between power, energy and time, we can find the energy delivered by the laser in 1 second:

The frequency of the photons of this light is given by

and the energy of a single photon is

In order to find the number of photons emitted per second, we must divide the total energy emitted by the laser by the energy of a single photon, and we get:
Whenever light goes from transparent to another medium or from rarer to denser medium or vice versa, it's speed changes and hence light bends.
- momentum
- Yes, if the elephant is standing still.
- Fullback
- impulse acting on it.
- 2.25 N∙s
- A cannon firing.
- Inelastic
- it stays the same
- When the cue ball contacts the other balls, momentum is transferred causing them to gain momentum and speed.
- less than 3 m/s
<h3><u><em>
these are all correct i got an 100%</em></u><em><u> </u></em></h3>
<span>As long as both mirrors are set at 45% and the same size then you see the same as is reflected in the upper mirror </span>
<span>Put a lens in the middle of the tube </span>
<span>? </span>
<span>We use mirrors when we drive cars ect </span>
<span>Normally they are set across from a concealed entrance or one that is hard to see both ways like the inside of a hairpin bend. Sometimes only to help in one direction. </span>
<span>Sonar which is sound waves that are sent out at a set rate then reflected by objects. The longer the gap between the two the further away it is, They still use periscopes to target boats though. </span>
<span>The periscope can only reflect what is outside so if you could see it because there is enough light then Yes. If you could not see it because it is dark then No unless you get into Info-Red light or Image Intensifying systems as well </span>
True!!!!!!!!!!!!!!!!!!!!!