From laboratory measurements, we know that a particular spectral line formed by hydrogen appears at a wavelength of 486.1 nanometers (nm). The spectrum of a particular star shows the same hydrogen line appearing at a wavelength of 485.9 nm. What can we conclude

We conclude that star moving toward observer.

Explanation:

According to the theory of doppler effect of light.

There are two kind of shift 1 )  Blue shift 2 ) Red shift, in which

1 ) if source of light moving toward observer so the apparent frequency of light increase( wavelength decrease ). This is which we call blue shift

2 ) if the distance between source and observer is increase, so the apparent frequency of light decrease ( wavelength increase ). This is which we call red shift.

Here, in our case wavelength of H-star is decrease so we can say that star moving toward observer ( Blue shift ).

another example of kinetic energy would be,

kinetic energy   >     moving energy

answer   >   letter choice (c),   a hammer falling off a table.

hope that !                                         : )

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27