The h line in calcium is normally at 396.9 nm. however, in a star's spectrum, it is measured at 398.1nm. how fast is the star moving and is it moving towards the earth or away from the earth? 1- 904.3 km/s away from the earth 2- 904.3 km/s towards the earth 3- 907.0 km/s towards the earth 4- 907.0 km/s away from the earth

As we know by Doppler's effect of light we have

here we will have

[tex}\frac{398.1 nm - 396.9 nm}{398.1 nm} = \frac{v}{c}[/tex]

here by solving above we have

here we have

since wavelength is increased so we can say that it is moving away

so correct answer is

1- 904.3 km/s away from the Earth

50 inches should be the resultant vector

f is prop to m1xm2 double m1 double force