Question

n hydrogen, the transition from level 1 to level 2 has a rest wavelength of 121.6 nm. Suppose you see this line at a wavelength of 124.2 nm in a Star. What is the velocity of this in the direction of the Earth?

Answer 1

Answer:

velocity of this in the direction of the Earth is 6.4 × $10^{6}$  m/s

Explanation:

given data

wavelength $\lambda 1$ = 121.6 nm

wavelength $\lambda 2$ = 124.2 nm

solution

we get here first change in wavelength that is

$\triangle \lambda$ = 124.2 nm - 121.6 nm    ...............1

$\triangle \lambda$ = 2.6 nm  

we get here velocity of direction of the Earth that is express as

$\frac{\triangle \lambda }{\lambda 1} =\frac{v}{c}$     ............2

put here value we get v

v = $\frac{3\times 10^8\times 2.6}{121.6}$    

v = 6.4 × $10^{6}$  m/s