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,
Given:
The initial velocity of the object, v=30 m/s
a_t=0
a_c≠0
The time period is Δt.
To find:
The right conclusion among the given choices.
Explanation:
a_t represents the tangential accleration on the object and a_c represents the centripetal acceleration on the object.
The centripetal acceleration is the acceleration that keeps the object in its circular path. The centripetal force only changes the direction of the velocity and not the magnitude.
Thus the magnitude of the velocity of the object remains the same after a time interval of Δt. But the direction of the velocity of the object will be changed and will be unknown after Δt seconds.
Final answer:
Thus the object will be traveling at 30 m/s in some unknown direction.
Therefore, the correct answer is option a.
True, when charging a secondary cell, energy can be stored within a dielectric material using an electric field.
<h3>Relationship between dielectric material and electric field</h3>
The electric field in a capacitor separates the negative and positive charges in the dielectric material, this causes an attractive force between each plate and the dielectric.
The dielectric material can store electric energy due to its polarization in the presence of external electric field, which causes the positive charge to store on one electrode and negative charge on the other.
Thus, when charging a secondary cell, energy can be stored within a dielectric material using an electric field.
Learn more about dielectric material here: brainly.com/question/17090590
Yes. Kinetic energy is a form of mechanical energy and friction will turn that kinetic energy into heat.
Answer:
14
Explanation:
A sound wave in a steel rail has a frequency of 620 Hz and a wavelength of 10.5 m. What is the speed of sound in steel? U f = ? S f = 3 x 108 m/s) / 0.06 m 14 so it will be 14
