CUET Preparation Today
A star is moving away from earth and shift in spectral line of wavelength 5700 Ao is 1.90Ao. Velocity of the star is |
50 km s–1 70 km s–1 80 km s–1 100 km s–1 |
100 km s–1 |
$\Delta \lambda = \frac{v}{c}\lambda $ $\Rightarrow v = \frac{\Delta \lambda}{\lambda}c = \frac{1.9}{5700} 3\times 10^8 = 10^5m/s = 100km/s$ |
