**CENTRIPETAL FORCE**** & GRAVITY=
UN=
ITS**** 8 & 14**

**Dr. John P. Cise, Pro=
fessor
of Physics, **

**& **

**-------------------------------------------------=
---------------------------------------------------------------------------=
----------------------------**

**Question: This new found plan=
et(Gliese 581e) might be EARTHLIKE. The period(T)of
Gliese 581e about it’s red dwarf star(usu=
ally
about 1/3 the mass of the earth’s sun …..ea=
rth’s
sun mass =3D 2 X 10*30 kg.) <=
span
class=3DGramE>is given below as 13 days and distance(R) from it̵=
7;s
sun as seven million miles. With this planet’s R and T find the mass of this planetR=
17;s
sun?**

**Hint: Use Kepler’s 3 ^{rd}
law which comes from Gravity(GmM/R*2)
providing the centripetal force…m V*2/R. Thus…M =3D [4 pi *2/G]
R*3/T*2 . This found planet is exciting. Dr. Cis=
e.**

**Answer: 0.666 X 10 * 30 kg……this is t=
he
usual mass of a red dwarf.**

**_________________________________________________=
___________________________________________________**

New
Planet Could Be Earthlike, Scientists Say

<= o:p>