How fast a person should drive his car so that the red signal fo light apperas green ?
( Wavelength for red colour = 6200 Å and wavelength for green colour = 5400 Å)

Answer

`3.87 xx 10^(4) km/s`, No

Explanation

Apparent wavelength becomes
`lambda_(ap) = lambda_(0) - v((lambda_0)/(c))` `lambda_(ap) = lambda_(0) (1-(lambda_0)/(c))`
`540 = 620 (1 - (v)/(c))`
` 1 - (v)/(c) = (27)/(31)`
`(v)/(c) = (4)/(31)`
`v = (4)/(31) xx 3 xx 10^(8) = 3.87 xx 10^(7) m//s`
As this speed in much higher then escape velocity on earth. This is not attainable