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Sliva [168]
3 years ago
8

1. An excited lithium atom emits a red light with wavelength a = 671nm. What is the corresponding photon energy? hc (6.63 x 10-3

4).S)(3.0 x 108m/s)​
Physics
1 answer:
Rudiy273 years ago
6 0

Answer:

 E = 2,964 10⁻¹⁹ J

Explanation:

The energy of the photons is given by 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

let's reduce the magnitude to the SI system

          λ = 671 nm = 671 10⁻⁹ m

let's calculate

          E = 6.63 10⁻³⁴ 3 10⁸ /671 10⁻⁹

          E = 2,964 10⁻¹⁹ J

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Answer:

88.8 m/s= Speed of wave propagation in the required mode.(3 loops)

Explanation:

When there are 3 loops.  

the total length = L = 3 λ /2

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Velocity = v = f λ = (120)(0.74) = 88.8 m/s

3 0
3 years ago
The diagram below shows a circuit with a
kirill [66]

Answer:

15v

Explanation:

V = IR

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4 0
2 years ago
You stand on a merry-go-round which is spinning at f = 0.25 revolutions per second. You are R = 200 cm from the center. (a) Find
wariber [46]

Answer:

a) ω = 9.86 rad/s

b) ac = 194. 4 m/s²

c) minimum coefficient of static friction, µs = 19.8

Explanation:

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1 rps = 6.283 rad/s, π = 3.142

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ω = 9.86 rad/s

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a = 2 * 9.86²

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c) µs = frictional force/ normal force

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normal force = mg; where g = 9.8 m/s²

µs = ma/mg = a/g

µs = 194.4 ms⁻²/9.8 ms⁻²

c) minimum coefficient of static friction, µs = 19.8

5 0
2 years ago
HELPPP IM DESPERATE
damaskus [11]

the first one cuz I know

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2 years ago
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Hi I need help with some questions I have on a quiz / test
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3 years ago
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