Answer:
the charge carriers have an energy 2.8 10⁻¹⁹ J
Explanation:
The energy in a diode is conserved so the energy supplied must be equal to the energy emitted in the form of photons.
The energy of a photon is given by the Planck expression
E = h f
the speed of light, wavelength and frequency are related
c = λ f
we substitute
E = 
a red photon has a wavelength of lam = 700 nm = 700 10⁻⁹ m
we calculate the energy
E = 6.626 10⁻³⁴ 3 10⁸/700 10⁻⁹
E = 2.8397 10⁻¹⁹J
therefore the charge carriers have an energy 2.8 10⁻¹⁹ J,
Answer:
D. Electricity will flow if the electrons are bound loosely to their atoms in the material.
Explanation:
The continuous flow of charges is known as electricity (current). The flow of these charges are due to free or mobile electron within the atoms of the conductors. The materials which will allow current to pass through them, must have free or mobile electrons which are loosely bound to their atoms.
Thus, the correction for this question is "D"
D. Electricity will flow if the electrons are bound loosely to their atoms in the material.
Answer:
2.84 m/s
Explanation:
At the top position of the circular trajectory, the normal reaction is zero:
N = 0
So it means that the only force that is providing the centripetal force is the gravitational force (the weight of the bucket). Therefore we have:
where
m is the mass of the water bucket
g = 9.8 m/s^2 is the acceleration of gravity
v is the speed of the bucket
r = 0.824 m is the radius of the circle
Solving for v,
The correct answer is
C. Light can pass through Object B faster than it can pass through Object A.
In fact, the index of refraction of a material is defined as:
where c is the speed of light in vacuum and v is the speed of light in the material. Rearranging the equation, we can write the speed of light in the material as:
So we that, the smaller the refractive index n, the greater the speed of light in the material, v. In this problem, object B has lower refractive index than object A, so light travels faster in object B.
You said that she's losing 1.9 m/s of her speed every second.
So it'll take
(6 m/s) / (1.9 m/s²) = 3.158 seconds (rounded)
to lose all of her initial speed, and stop.
