Question

a spaceship is traveling at a speed of 15000 km/s from planet b toward planet a the spaceship sends out a signal with a wavelength og 4 nm if astronomers living on planets a and b measure the radio waves coming from the spaceship what wavelengths will they measure?

Answer 1

Answer: 4nmeter

Explanation: The two observer a and b will measure the same wavelength since the speed of the space craft is very small compared with the speed of light c. That is

V which is the speed of space craft 15000km/s = 15000000m/s

Comparing this with the speed of light c 3*EXP(8)m/s we have

15000000/300000000

= 0.05=0.1

Therefore the speed of the space craft V in terms of the speed of light c is 0.1c special relativity does not apply to object moving at such speed. So the wavelength would not be contracted it will remain same for both observers.

Answer 2

Answer:of

Astronomers living on planets a measure λO = 3.80_nm

Astronomers living on planets b measure λO = 4.2_nm

Explanation:

Astronomers living on planets a measure λO = 3.80_nm

Astronomers living on planets b measure λO = 4.2_nm

a.) Speed of the radio wave

c = 299792458 m/s.

λO = λS(c − vS)/(c − vO)

λO = observed wavelength

λS = source constant wavelength = 4 nm

c = wavefront constant velocity = 299792458 m/s

vS = velocity of the source = 15000 km/s

vO = velocity of the observer 0