Answer:
Every object in the universe that has mass exerts a gravitational pull, or force, on every other mass. The size of the pull depends on the masses of the objects. You exert a gravitational force on the people around you, but that force isn't very strong, since people aren't very massive.
Answer:
The answer to the first one is, group 1.
Explanation:
Sorry if this didn’t help if I find the answers to the others I’ll comment them to myself!
Answer:
b) the refracted ray has an angle of 90 degrees
Explanation:
The angle of incidence is measured with respect to the normal separation of the media. The critical angle for total internal reflection occurs is:
Here 
and 
are the refractive index of the mediums. This equation is an application of Snell's law, for the case where the refracted ray has an angle of 
.
