72 Km/hr
= 72000 m/ 60×60 s
= 72000 m/ 3600 s
= 20 m/s
Answer is 20 m/s.
Hope it helps! Please do comment
Known values; mass per / volume and mass of each atom
average volume=<span> volume per atom. </span>
<span>density*mass per atom = volume per atom </span>
<span>1cm^3 / 7.87 gram * 9.27 *10^-26 kg /atom* 1000 gram / kg=
</span>=<span>1.178 * 10^-22 cm^3 per atom </span>
<span>Convert that to mass </span>
<span>1 cm^3 * (1 m / 100 cm)^3 </span>
average volume= <span>1.178 *10^-29 m^3 per atom </span>
<span>distance: </span>
<span>Volume of a cube is L^3 </span>
<span>so L = (1.178*10^-29)^(1/3) </span>
<span>Half way through the cube is distance 1/2 L. </span>
<span>Second cube is 1/2 L </span>
<span>So distance between the center of 2 cubes = L </span>
=2.28 *10^-10 m
Therefore, the ball has a velocity of 4m/s.
Ignoring air resistance, the Kinetic energy before hitting the ground will be equal to the potential energy of the Piton at the top of the rock.
So we have 1/2 MV^2 = MGH
V^2 = 2GH
V = âš2GH
V = âš( 2 * 9.8 * 325)
V = âš 6370
V = 79.81 m/s
Na is in the first column on the periodic table so therefore it would have 1 valence electron
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