0 Members and 1 Guest are viewing this topic.

Sorry Kryptid, but I'm actually with sorlov on this one. The two forces are equal and opposite, one acting on the planet (thus slowing it down on its way out to aphelion), and the other acting on the primary (star presumably), slowing it down as well. The planet slows down not because the forces are not equal, but because the force is not acting tangentially to its motion.

I realize (due to Newton's third law), that the gravitational force on the planet must be equal and opposite to the gravitational force on the Sun. Likewise, the centrifugal force on the planet and the Sun must also be equal and opposite. But must this mean that the gravitational force between the Sun and planet are always equal to the centrifugal force between the Sun and planet?

How can the planet and Sun accelerate away from each other if there is no net force present between them?

F=ma seems to demand a net force in order for an acceleration to be present.

Это просто сила тяжести, одна масса действует на другую, каждая ускоряет другую.

Quote from: HalcIt's just a force of gravity, one mass acting on another, each accelerating the other.Unfortunately, you did not understand my theory. I wasn't commenting on your theory. I was replying to Kryptid.

It's just a force of gravity, one mass acting on another, each accelerating the other.