1. As telescopes improve, astronomers are able to detect planets orbiting other stars. One such planet orbits its star at a distance of 2.897 x 109 km. (This is far enough from the star that radius of the star can be ignored.) The star has 1.9 times the mass of our sun (msun = 2 x 1030 kg). If the planet has a mass of 5.4 x 1027 kg, what is the force of gravity it experiences

The planet will experience a force of

Explanation:

The force of gravity experienced by the planet is of mass at a distance from a star of mass is given by

where is the gravitational constant.

The mass of the star is two times that of the sun:

,

the mass of the planet is

,

the distance of the planet form the star is

;

therefore, the force of gravity on the planet will be

which is the force that the planet will experience.

b. lifting dumbbell weight at 20-degree angle from the body after a 45-degree angle

3. dark matter

empty space could also be a simple vacuum