With what speed should a galaxy move with respect to the earth so that sodium line at 589 nm is observed at 589.6nm?

A jet airplane travelling at the speed of 500 km h-1 ejects its products of combustion at the speed of 1500 km h-1 relative to the jet plane. What is the speed of the latter with respect to an observer on ground?

What is blue shift? Sodium light of wavelength 589.0overset(@)A travelling from a galaxy is observed to be 589.6overset(@)A . What is the speed of the galaxy?

A man throws balls with the same speed vertically upwards one after another at an interval of 2 seconds. What should be the speed so that more than two balls are in the sky at any time? ( g = 9.8ms^-2 )

Two billiard balls each of mass 0.05 kg moving in opposite directions with speed 6 m s~1 collide and rebound with the same speed. What is the impulse imparted to each ball due to the other?

The spectral line at 434 nm in the Balmer series of the hydrogen spectrum corresponds to a transition from nth orbit. What is the value of n?

The focal lenghts of objectives and eyepiece of a telescope are 200cm and 10 cm respectively. Is is used to get an image of the Sun on a screen placed 40cm behind the eyepiece. The diameter of the image is 6cm. What is the diameter of the Sun? Give the distance from earth to the Sun is 1.5xx10^(11)m .