Answer: friction
Explanation:
Because when you rub to objects together it creates static electricity
Answer:
electromagnetic wave. this energy is what lights the bulb.
Explanation:
When you close an electrical circuit, the electrons have a small drag speed, but the fluctuation of the electric field that is created originates by Lenz's law a magnetic field and the appearance of this magnetic field creates a fluctuating elective field, these two fields together forms a wave called an electromagnetic wave.
This electromagnetic wave has a speed given by the relation
v = √1 /ε μ
in a vacuum this speed is equal to the speed of light, which is worth 3 10⁸ m/s this very high value so the energy transported by this wave can travel the distance of 10 m in less than 10⁻⁷ s, This energy is what lights the bulb.
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:
Inverse Square Law Newton proposed the Inverse Square Law. The effect of gravity (and also on forces such as sunlight) works like this. If say we have a half-mass Earth, it would produce a gravity of not half but a quarter (the square of 2).
Answer:
C. 640
Explanation:
The minimum force would occur in a frictionless environment and act parallel to any abutting surface.
F = ma = 160(4) = 640 N
