Answer:
#_photons = 30 photons / s
Explanation:
Let's start by finding the energy of a photon of light, let's use the Planck relation
E = h f
the speed of light is related to wavelength and frequency
c = λ f
we substitute
E = h c /λ
E₀ = 6.63 10⁻³⁴ 3 10⁸/500 10⁻⁹
E₀ = 3.978 10⁻¹⁹ J
now let's use a direct proportion rule. If the energy of a photon is Eo, how many fornes has an energy E = 1.2 10⁻¹⁷ J in a second
#_photons = 1 photon (E / Eo)
#_photons = 1 1.2 10⁻¹⁷ /3.978 10⁻¹⁹
#_photons = 3.0 10¹
#_photons = 30 photons / s
Answer:
what.....................
i edited this answer
please mark me as brainlist
An electric engine turning a workshop sanding rotation at 1.00 × 10² rev/min is switched off. Take the wheel includes a regular negative angular acceleration of volume 2.00 rad/s². 5.25 moments long it takes the grinding rotation to control.
<h3>What is negative angular acceleration?</h3>
- A particle that has a negative angular velocity rotates counterclockwise.
- Negative angular acceleration () is a "push" that is hence counterclockwise.
- The body will speed up or slow down depending on whether and have the same sign (and eventually go in reverse).
- For instance, when an object rotating counterclockwise slows down, acceleration would be negative.
- If a rotating body's angular speed is seen to grow in a clockwise direction and decrease in a counterclockwise direction, it is given a negative sign.
- It is known that a change in the linear acceleration correlates to a change in the linear velocity.
Let t be the time taken to stop.
ω = 0 rad/s
Use the first equation of motion for rotational motion
ω = ωo + α t
0 = 10.5 - 2 x t
t = 5.25 second
To learn more about angular acceleration, refer to:
brainly.com/question/21278452
#SPJ4
Complete question:
The exit nozzle in a jet engine receives air at 1200 K, 150 kPa with negligible kinetic energy. The exit pressure is 80 kPa, and the process is reversible and adiabatic. Use constant specific heat at 300 K to find the exit velocity.
Answer:
The exit velocity is 629.41 m/s
Explanation:
Given;
initial temperature, T₁ = 1200K
initial pressure, P₁ = 150 kPa
final pressure, P₂ = 80 kPa
specific heat at 300 K, Cp = 1004 J/kgK
k = 1.4
Calculate final temperature;

k = 1.4

Work done is given as;

inlet velocity is negligible;

Therefore, the exit velocity is 629.41 m/s