Posted by **Ashley** on Wednesday, January 30, 2013 at 6:19pm.

Calculate the kinetic energy that the earth has because of (a) its rotation about its own axis and (b) its motion around the sun. Assume that the earth is a uniform sphere and that its path around the sun is circular. For comparison, the total energy used in the United States in one year is about 1.1 x 1020 J.

- Physics -
**Elena**, Wednesday, January 30, 2013 at 6:30pm
(a) KE(rot) =I ω²/2

I=2MR²/5

ω=2π/24•3600 = ...(rad/ s)

Earth’s mass is M = 5.97•10²⁴kg,

Earth’s radius is R = 6.378•10⁶ m.

(b)

Linear velocity of the Earth is

v=ωr = 2π• 1.496•10¹¹ /365•24•3600 = …m/s

KE=Mv²/2 =5.97•10²⁴• (2π• 1.496•10¹¹ /365•24•3600)²/2 = …J

- Physics -
**Ashley**, Wednesday, January 30, 2013 at 7:15pm
Thanks!! Clears up everything

## Answer This Question

## Related Questions

- physics - please help - Assume the earth is a uniform sphere and that its path ...
- Physics - Assume that the earth is a uniform sphere and that its path around the...
- physics - Assume that the earth is a uniform sphere and that its path around the...
- Physics - Calculate the kinetic energy that the earth has because of (a) its ...
- PHYSICS - Calculate the kinetic energy that the earth has because of (a) its ...
- Physics - Calculate the kinetic energy that the earth has because of (a) its ...
- Physics - Calculate the kinetic energy that the earth has because of (a) its ...
- Physics - Calculate the kinetic energy that the earth has because of its ...
- Physics- drwls please help - (a) Calculate the kinetic energy that the earth has...
- Physics - (a) Calculate the kinetic energy that the earth has because of its ...

More Related Questions