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 radius is in Kilometers.

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.

Authors Note:


My books on Kindle:

Solving Finance Problems In Excel;

Book solves 15 practical finance problems in Excel

Nine Essays on Debt and Your Retirment

Book argues that debt reduction and management needs to take priority over investing in risky assets and buying the dream house.


If you are saving for retirement you may want to look at my finance blog:

Thinking about investing some of your 401((k) in an emerging market fund.   Read this post first.
http://financememos.blogspot.com/2016/01/investing-in-emerging-markets-post-1.html





No comments:

Post a Comment