Answer:
Explanation:
energy emitted by source per second = .5 J
Eg = 1.43 eV .
Energy converted into radiation = .5 x .12 = .06 J
energy of one photon = 1.43 eV
= 1.43 x 1.6 x 10⁻¹⁹ J
= 2.288 x 10⁻¹⁹ J .
no of photons generated = .06 / 2.288 x 10⁻¹⁹
= 2.6223 x 10¹⁷
wavelength of photon λ = 1275 / 1.43 nm
= 891.6 nm .
momentum of photon = h / λ ; h is plank's constant
= 6.6 x 10⁻³⁴ / 891.6 x 10⁻⁹
= .0074 x 10⁻²⁵ J.s
Total momentum of all the photons generated
= .0074 x 10⁻²⁵ x 2.6223 x 10¹⁷
= .0194 x 10⁻⁸ Js
b ) spectral width in terms of wavelength = 30 nm
frequency width = ?
n = c / λ , n is frequency , c is velocity of light and λ is wavelength
differentiating both sides
dn = c x dλ / λ²
given dλ = 30 nm
λ = 891.6 nm
dn = 3 x 10⁸ x 30 x 10⁻⁹ / ( 891.6 x 10⁻⁹ )²
= 11.3 x 10¹² Hz .
c )
10 nW = 10 x 10⁻⁹ W
= 10⁻⁸ W .
energy of 50 dB
50 dB = 5 B
I / I₀ = 10⁵ ; decibel scale is logarithmic , I is energy of sound having dB = 50 and I₀ = 10⁻¹² W /s
I = I₀ x 10⁵
= 10⁻¹² x 10⁵
= 10⁻⁷ W
= 10 x 10⁻⁸ W
power required
= 10⁻⁸ + 10 x 10⁻⁸ W
= 11 x 10⁻⁸ W.
A soccer ball is traveling at a velocity of 50 m/s. The kinetic energy of the ball is 500 J.The mass of the soccer ball is 0.4 kgs. This answer is derived from the formula K=1/2 MV^2.So velocity and kinetic energy are given from that mass of the ball is calculated.By substituting the values 500=1/2*M*50*50 which gives M=0.4 Kgs.<span>
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An advertisement for an all-terrain vehicle (ATV) claims that the ATV can climb inclined slopes of 35°. The minimum coefficient of static friction needed for this claim to be possible is 0.7
In an inclined plane, the coefficient of static friction is the angle at which an object slide over another.
As the angle rises, the gravitational force component surpasses the static friction force, as such, the object begins to slide.
Using the Newton second law;




N = mg cos θ
Equating both force component together, we have:



From trigonometry rule:

∴



Therefore, we can conclude that the minimum coefficient of static friction needed for this claim to be possible is 0.7
Learn more about static friction here:
brainly.com/question/24882156?referrer=searchResults
Answer:
Formation of new elements
Explanation:
The answer is letter c.
The explanation behind this is when human consumes a plant
or when a human being eats an animal that ate a plant. The chemical energy kept
in the plant (or animal) cells is progressed into the cells of the human's
body. All of the body progressions, like ingestion, breathing, pumping blood, are
driven by cells changing the kept chemical energy into heat and work, in a procedure
called respiration. In the muscle cells of the human (or any animal), the
chemical energy is converted into mechanical work and heat. The muscle pacts,
the legs thrust, and the body jumps into the air.