Is a planets gravity determined by how close it is to the sun?

Answer 1

Gravity is the force that pulls all objects towards the center of the earth. So the effect of gravity on moving objects is that it pulls them back towards the center of the earth, causing friction with the any surface beneath them.

Answer 2

The relationship is: Larger orbit ===> Longer period of revolution.

The numerical relationship is Kepler's third law:

For every object in orbit around the same central body (like the sun, for instance),

(the square of the orbital period) divided by (the cube of the distance)

is the same number, as long as you use the same units for each body.

Technically, the "distance" in that law is the semi-major axis of the ellipse that

the orbit follows. For the planets, their orbits are so close to being circles that

you can use their average distance from the sun, and not be too far off. But

that doesn't work for comets, whose orbits are very "eccentric" ellipses (more

egg-shaped).

Answer 3

As you move away from the sun, the time to complete an orbit increases. ============================================ In ANY system of small bodies orbiting a much larger body, the period of an orbit depends only the orbit's size, and NOT on the mass of the small orbiting bodies. Larger orbits have longer periods. The mathematical relationship is: T2 divided by R3 is a constant number for all of the small bodies in the system. 'T' is the period of the orbit ... the 'T'ime taken for one revolution. 'R' is the 'R'adius of the orbit, or the distance of the small orbiting body from the large central body. (Actually the semi-major axis of the elliptical orbit.)

Answer 4

Orbital velocity is inversely to the distance from the primary, and directly related to the mass of the primary. The bigger the star, the faster the orbit; the further the orbit, the slower. So Mercury, closest in to the Sun, orbits fastest, and Venus next. Pluto takes centuries to orbit the Sun once.

Answer 5

Yes and No.

More massive planets have a stronger gravitational pull. Often larger planets are more massive than smaller ones, but that does not always have to be true! You can have a large planet with a low density.

Size, as the distance across the planet's diameter, has a small inverse effect on the gravitational pull of the planet - the gravity is lower further away from the "center of gravity" which in the case of a planet is at the center of the (almost) spherical body.

Answer 6

Kepler's "laws of motion" describe the fact that gravitational bodies move in elliptic paths where the sun occupies one focus and the area swept out by the line between the orbiting planet and the sun is equal for any given time interval. So thirty days, when the planet is furthest from the sun, sweeps over the same area that thirty days when it is closest. Thus the angular change during the month at close approach, as seen from the sun, is greater than when the planet is further away. The orbital speed is necessarily greater then too.

Answer 7

The answer seems obvious. Planets move in roughly circular orbits.

If the planet is further from the Sun, the radius of the circle is bigger. Therefore he circumference of the circle is bigger.

So, the length of the orbit is bigger.

But perhaps you meant the length of time to complete the orbit.

In that case there are 2 reasons:

1) The planet has further to travel, as explained.

2) The further the planet is from the Sun, the more slowly it moves.

This was described mathematically by Johannes Kepler about 400 years ago in his Laws of Planetary Motion.

Kepler got his Laws purely from observations. Later, Isaac newton derived

them from his work on gravitation and mechanics.

Answer 8

Do you mean size or mass(weight) as the larger the mass the larger the gravitational attraction. That's why when a person stands on a weighing scale the heavier they are the more they are attracted by gravity toward the centre of the earth so the greater the reading on the scale. SIMPLES.

Answer 9

Any object in orbit will follow some very precise laws:

The closer the orbit is, the faster it is completed, but its tangential velocity is slower.

If an object is in a low orbit, and has a prograde increase in Delta-V, it will result in a higher orbit. Which would take longer to complete, but its tangential velocity is actually greater.

When this occurs naturally, like with planets orbiting the sun, those planets closer to the sun will complete an orbit (better called a "revolution") sooner than planets further away.

But, those planets that are further away will have a faster tangential velocity, because their orbits cover a larger circumference, but it results in more time needed to complete one orbit.

Answer 10

No, the shape of a planet's orbit does not depend upon its speed, although the shape of the orbit does affectthe speed. In a highly elliptical orbit, the planet will move faster when it is close to the sun, and slower when it is farther from the sun. In a more circular orbit, the distance from the sun doesn't significantly change, therefore, neither does the speed of the orbit. You should understand that it is the distance of an orbit from the sun, not the shape of the orbit, which determines the speed of the orbit. The closer to the sun, the faster the orbit. The shape of an orbit results only from the momentum that the planet had when it first formed (possibly altered by later collisions with relatively large objects).