Answer:
Acceleration, in m/s, of such a rock fragment = 
Explanation:
According to Newton's Third Equation of motion
Where:
is the final velocity
is the initial velocity
a is the acceleration
s is the distance
In our case:
So Equation will become:
Acceleration, in m/s, of such a rock fragment =
A device used to initiate and control a sustained nuclear chain reaction.
Answer:
finding Cepheid variable and measuring their periods.
Explanation:
This method is called finding Cepheid variable and measuring their periods.
Cepheid variable is actually a type of star that has a radial pulsation having a varying brightness and diameter. This change in brightness is very well defined having a period and amplitude.
A potent clear link between the luminosity and pulsation period of a Cepheid variable developed Cepheids as an important determinants of cosmic criteria for scaling galactic and extra galactic distances. Henrietta Swan Leavitt revealed this robust feature of conventional Cepheid in 1908 after observing thousands of variable stars in the Magellanic Clouds. This in fact turn, by making comparisons its established luminosity to its measured brightness, allows one to evaluate the distance to the star.
I am sure it is frequency
