## Sunday, January 10, 2016

### Planet Density and Mass Problems

The Table below contains data on the radius and mass of the planets (including poor Pluto) and the sun?

The mass is in Kilograms.

 Radius (km) Mass (kg) Sun 695000 1.99E+30 Mercury 2440 3.30E+23 Venus 6052 4.87E+24 Earth 6378 5.97E+24 Mars 3397 6.42E+23 Jupiter 71492 1.90E+27 Saturn 60268 5.68E+26 Uranus 25559 8.68E+25 Neptune 24766 1.02E+26 Pluto 1150 1.27E+22

Here are some questions:

What is the density of each planet and the sun?   Express the answer in kilograms per cubed meter.

How many earths are equal to the weight of Jupiter?

What weighs more the sum of the weight of all planets or the weight of the sun?

Questions:

Question:   What is the density of each planet and the sun?

The volume of a sphere is V=(4/3) pi r3

Under the assumption that each planet is a perfect sphere we can use this formula to the volume of each planet.

Dividing mass of the planet by volume gives us density in kg/km3.

Dividing by 1/10003 gives us the answer in km/m3.

 Density of Planets and Sun Radius (km) Mass (kg) Volume Km3 Density in kg/km3 Density in kg/m3 Mercury 2440 3.3E+23 6.08E+10 5.42E+12 5.42E+03 Venus 6052 4.87E+24 9.29E+11 5.24E+12 5.24E+03 Earth 6378 5.97E+24 1.09E+12 5.49E+12 5.49E+03 Mars 3397 6.42E+23 1.64E+11 3.91E+12 3.91E+03 Jupiter 71492 1.9E+27 1.53E+15 1.24E+12 1.24E+03 Saturn 60268 5.68E+26 9.17E+14 6.19E+11 6.19E+02 Uranus 25559 8.68E+25 6.99E+13 1.24E+12 1.24E+03 Neptune 24766 1.02E+26 6.36E+13 1.60E+12 1.60E+03 Pluto 1150 1.27E+22 6.37E+09 1.99E+12 1.99E+03 Sun 695000 1.99E+30 1.41E+18 1.42E+12 1.42E+03

Question: How many earths does it take to equal the weight of Jupiter?

Divide the weight of Jupiter by the weight of the earth.

1.9 x1027/ 5.97x1024

318.3

Question what weighs more the sum of all the weight of all planets or the weight of the sun?

The sun weighs more.   I don’t need to add.   The mass of the sun in scientific notation is roughly 1000 times higher than the mass of the largest planet Jupiter.  Compare 1030 to 1027.  Since the sun weighs more than 1000 times Jupiter, the heaviest planet, it must also weigh more than the sum of nine planets.

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