Volcano
A planet gets its force of gravity from its mass and the distance from its center. The more massive the planet, the stronger its gravitational pull will be. Gravity is a fundamental force of nature that attracts all objects with mass towards each other.
A force that most affects the path of a planet around the Sun is gravity.
The fundamental source of energy on Earth is the sun. Solar energy is the primary driver of most natural processes and life on our planet.
It is Jupiter.
Gravitational force between Earth - Moon - Sun is the fundamental force behind the tidal motion.
Gravitational force is the weakest fundamental force in nature. It is significantly weaker than the strong nuclear force, weak nuclear force, and electromagnetic force.
Fundamental forces are the four fundamental interactions in nature (gravity, electromagnetism, strong nuclear force, and weak nuclear force) that govern particle interactions at a fundamental level. Non-fundamental forces are derived from these fundamental forces, such as friction or tension, that arise from interactions at a macroscopic level.
The electroweak force is the unification of the electromagnetic force and the weak nuclear force, two of the four fundamental forces in nature.
The fundamental consideration to examine when organizing a force is what is the purpose of the force. Other things to consider is experience and mobility.
"Negative gravity" is not a scientific concept. Gravity is a fundamental force of attraction between masses. "Positive gravity" is simply the normal gravitational force experienced on Earth, pulling objects towards the center of the planet.
The easiest to observe would probably be gravity, just drop something!
I think because it is the largest planet.