<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>
Answer:
a) P=0.25x10^-7
b) R=B*N2*E
c) N=1.33x10^9 photons
Explanation:
a) the spontaneous emission rate is equal to:
1/tsp=1/3 ms
the stimulated emission rate is equal to:
pst=(N*C*o(v))/V
where
o(v)=((λ^2*A)/(8*π*u^2))g(v)
g(v)=2/(π*deltav)
o(v)=(λ^2)/(4*π*tp*deltav)
Replacing values:
o(v)=0.7^2/(4*π*3*50)=8.3x10^-19 cm^2
the probability is equal to:
P=(1000*3x10^10*8.3x10^-19)/(100)=0.25x10^-7
b) the rate of decay is equal to:
R=B*N2*E, where B is the Einstein´s coefficient and E is the energy system
c) the number of photons is equal to:
N=(1/tsp)*(V/C*o)
Replacing:
N=100/(3*3x10^10*8.3x10^-19)
N=1.33x10^9 photons
Answer:
20 N
Explanation:
In air, the normal force is equal to the weight.
∑F = ma
N − mg = 0
N = mg
Submerged in water, the normal force is equal to the weight minus the buoyant force:
∑F = ma
B + N − mg = 0
N = mg − B
Plugging in values:
80 N = 100 N − B
B = 20 N
Answer:
The velocity of the recoil is 
Explanation:
Kinetic Energy

The mass of th gun is the both mass the shotgun and the arm shoulder combination

The velocity is negative because is in opposite direction of the bullet
Answer:
the force of attraction between all masses in the universe
Explanation:
<em>Have a nice day </em>:)