Answer:
Read below!
Explanation:
You can watch the sun wheel across the sky during the day, and the stars at night. Focus a telescope on any star besides the north star--especially southern stars--and you can watch them drift across your field of view.
An alternative explanation is that all the stars are painted on (or holes in) some canopy that rotates around the earth. This explanation does not account for the motion of the "wanderers," or planets, as the Greeks called them, or for the path of the moon among the stars.
As we know the stars are massive bodies of significant and varying distance to the earth, the notion they all swing around us in unison seems highly implausible
Answer:
The center of mass of the Earth-Moon system is 4.673 kilometers away from center of Earth.
Explanation:
Let suppose that planet and satellite can be treated as particles. The masses of Earth and Moon (
,
) are
and
, respectively. The distance between centers is 384,403 kilometers. The location of the center of mass can be found by using weighted averages:

If
and
, then:


The center of mass of the Earth-Moon system is 4.673 kilometers away from center of Earth.
D. 128.25 because force=mass x acceleration
Answer:
675J
Explanation:
Given parameters:
Force = 45N
Distance = 15m
Unknown:
Work done by Sheila = ?
Solution:
Work done by a body is the amount of force applied to make a body move through a distance;
Work done = Force x distance
Now;
Work done = 45 x 15 = 675J