The North Star, or Polaris, is the brightest star in the constellation Ursa Minor, the little bear (also known as the Little Dipper). As viewed by observers in the Northern Hemisphere, Polaris occupies a special place

5 0

3 years ago

All phase changes are .an example of a phase change is an ice cube melting

masha68 [24]

Answer:

Explanation:

8 0

3 years ago

AM radio waves have longer wavelength than FM radio waves? true or false?

Mars2501 [29]

Answer:

true

Explanation:

the wavelength of AM radio is 10 m whereas FM has 1 m

8 0

2 years ago

A laser pulse of duration 25 ms has a total energy of 1.4 J. The wavelength of this radiation is

SpyIntel [72]

Answer:

n = 4 x 10¹⁸ photons

Explanation:

First, we will calculate the energy of one photon in the radiation:

$E = \frac{hc}{\lambda}\\\\$

where,

E = Energy of one photon = ?

h = Plank's Constant = 6.625 x 10⁻³⁴ J.s

c = speed of light = 3 x 10⁸ m/s

λ = wavelength of radiation = 567 nm = 5.67 x 10⁻⁷ m

Therefore,

$E = \frac{(6.625\ x\ 10^{-34}\ J.s)(3\ x\ 10^8\ m/s)}{5.67\ x\ 10^{-7}\ m}$

E = 3.505 x 10⁻¹⁹ J

Now, the number of photons to make up the total energy can be calculated as follows:

$Total\ Energy = nE\\1.4\ J = n(3.505\ x\ 10^{-19}\ J)\\n = \frac{1.4\ J}{3.505\ x\ 10^{-19}\ J}\\$

<u>n = 4 x 10¹⁸ photons</u>

8 0

3 years ago