Answer:
F in the definition of potential energy is the force exerted by the force field, e.g., gravity, spring force, etc. The potential energy U is equal to the work you must do against that force to move an object from the U=0 reference point to the position r.
Explanation:
A black hole is a cosmological object that is created when a massive star comes to the end of its life and collapses under its own gravity. Black holes have massive gravitational fields that even light cannot escape beyond a certain distance. Before being engulfed, matter that is pulled into a black hole should become very hot and emit electromagnetic radiation.
Magnetic force obeys an inverse square law with distance. ... If the distance between two magnets is halved the magnetic force between them will increase to four times the initial value.
Answer:
Explanation:
Gravitational Potential Energy at earth surface 
Gravitational Potential Energy at height h is 
Energy required to lift the satellite 
Now Energy required to orbit around the earth
(given)
(b)For greater height 
is greater than 
thus energy to lift the satellite is more than orbiting around earth
B: Extension Lines! You could have just searched this up on google
