The only correct statement on the list is choice-A./
Answer:
Doppler shift of the starlight
Explanation:
To predict the movement of a star, we compare the spectra of elements found in star (H, He Na etc.), first spectra which are obtained from star and second spectra from laboratory. If spectral lines of the spectra obtained from star, are shifting towards red end (called red shift) then star is going away from earth and if shifting is towards blue (called blue shift), then star is approaching the earth. This is Doppler's shift.
Answer:
12500W
Explanation:
Given parameters:
Work done = 250000J
Time taken = 20s
Unknown:
Power of the crane = ?
Solution:
Power is the defined as the rate at which work is being done;
Mathematically;
Power = 
insert the parameters and solve;
Power = 
= 12500W
Answer:1.55 times
Explanation:
Given
First wavelength
Second wavelength
According wien's diplacement law
where 
T=Temperature
Let 
be the temperatures corresponding to 
respectively.
Thus object with 
is 1.55 times hotter than object with wavelength 
Answer:
what did u say and what language are you speaking in
