Answer:
The answer is 0.83 seconds.
Explanation:
The formula of free fall is following:

Where g=9.8 m/s^2 and t=2 seconds, the rock takes:

19.6 meters. This is the half distance of the cliff. The whole distance is 39.2 meters. So it takes:

2.83 second to fall down completely. The rock takes the second half of the cliff in 0.83 seconds
For the answer to the question above asking to d<span>etermine the density of the proton.
</span>Density is mass over volume.
The volume of a sphere is 4πr³/3. r is half the diameter.
So the density would be 2.3×10¹⁷ kg/m³.
I hope my answer helped you. Feel free to ask more questions. Have a nice day!
The only real difference is that common seismic waves travel through the ground and sound waves travel through the air. If you had a pipe attached to granite and you were listening to it, you might detect both.
Explanation:
u=166m/s, v=0(at it's highest point final velocity is zero), a=9.8m/s², t=8.6s
by the formula, S=ut+½at².
S=[166×8.6+½.×9.8×(8.6)²]. ...by calculation
S = 1427.6+362.404
S=1790.004m
hope this helps you.