Answer:
They are orbiting earth.So they stay in orbit.
 We know that gravity increases with height.
Step-by-step explanation:
1st Question Explanation:
- Earth's gravity still pull on them. 
 - Gravity combines with the satellite's momentum from its launch into space.This Combination cause the satellite go into the orbit.
 
2nd Question Explanation:
- Gravity is caused by the Earth's spinning 
 - Gravity is notable bless on high mountains or tall buildings.