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fenix001 [56]
3 years ago
6

PLEASE HELP. HOW DO U CALCULATE??

Physics
1 answer:
tatyana61 [14]3 years ago
5 0

-- The energy of one photon is <em>(h · frequency of the light)</em>

' h ' is 6.626 × 10⁻³⁴ m²-kg/s  ("Planck's Constant")

-- The question doesn't tell you the frequency of the light from the LED, but it tells you the wavelength, and  

<em>Frequency = (speed of light) / (wavelength) </em>.

-- Now you have everything you need to calculate the <em>energy carried by one photon from the LED</em>.

-- The power of the light from the LED is 120 milliwatts.  That's <em>0.120 Joule of energy per second</em>.

Now you should be able to find the number of photons per second.  It's going to be  <em>(0.120 Joule) / (energy carried by one photon)</em> .


When I scribbled it out on a scrap of scratch paper, I got 3.853 x 10³⁸ photons, but you'd better really check that out.

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To which category does galaxy #1 belong? Why does it belong in this category?
vodka [1.7K]

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This galaxy belongs to the elliptical galaxy category. This is because it does not have spiral arms.

5 0
2 years ago
A flexible shaft consists of a 3 mm diameter steel wire in a flexible hollow tube which imposes a frictional torque of 0.04 N m
Rom4ik [11]

Answer:

2.5m

Explanation:

Torque is defined as the rotational effect of a force on a body.

The torque T for the maximum shear stress is given as 0.1 Nm

Frictional torque is the torque caused by a frictional force

The frictional torque F is given as 0.04 Nm/m

The maximum length of the shaft is thus given as

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6 0
3 years ago
A player at first base catches a throw traveling 38 m/s. The baseball, which has a mass of 0.145 kg, comes to a complete stop in
mixas84 [53]

Answer:

F = 39.36 N

Explanation:

given,

initial speed, u = 38 m/s

final speed, v = 0 m/s

mass of ball = 0.145 Kg

time, t = 0.14 s

Force = ?

using impulse formula

J = change in momentum

J = F x t

m(v - u) = F x t

0.145 x (0 - (-38)) = F x 0.14

F x 0.14 = 5.51

F = 39.36 N

force exerted by the ball is equal to 39.36 N.

5 0
3 years ago
A green truck is moving to the right. A red truck is moving to the left with a speed of 6 m/s. The mass of the red truck is 1,00
Contact [7]

Answer:

2 m/s

Explanation:

m_1 = Mass of red truck = 1000 kg

m_2 = Mass of green truck= 3000 kg

u_1 = Initial Velocity of red truck = 6 m/s

u_2 = Initial Velocity of green truck

v = Velocity with which they move together = 0

For elastic collision

m_1u_1 + m_2u_2 =(m_1 + m_2)v\\\Rightarrow m_1u_1 + m_2u_2 =0\\\Rightarrow m_1u_1 + m_2u_2 =(m_1 + m_2)v\\\Rightarrow m_1u_1 + m_2u_2 =0\\\Rightarrow u_2=-\frac{m_1u_1}{m_2}\\\Rightarrow u_2=-\frac{1000\times 6}{3000}\\\Rightarrow u_2=-2\ m/s

Velocity of the green truck is 2 m/s

8 0
2 years ago
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