Gravity Confusion ? Help Needed!?

Question

Why do you weigh mor eon the earth than you do on the moon?

Next Question is...

Why do satellites not fall down on earth?

I appreaciate every bit of help I can get, Thanks!

Answer 1

you weigh more on the earth because the earth is more massive than the moon. gravitational force is proportional to the both the mass of the object and the mass of the planet(or moon...).

satellites don't fall because they are in an orbit where their path forms an ellipse around the earth. even though they don't fall, earth's gravity is indeed exerting a force on the satellites, which is why they follow elliptical orbits as opposed to moving in straight lines. it's the same principle as to how the planets orbit around the sun without falling in.

Answer 2

Any object with mass has a gravitational pull. Earth has greater mass than the moon, therefore it has a stronger force of gravity. Your weight is the force that your body is imposing on the ground.
Force = Mass x Acceleration
which means
Your weight = your mass x accleration due to gravity.
Given the same mass, you will weigh more on Earth than on the moon as Earth has a higher gravitational pull.

The second problem is slightly different. If a satellite is moving fast enough at the right altitude, it ends up in a state of perpetual freefall around the earth - ie. it is constantly being pulled back to earth by gravity but is moving at such a speed it effectively misses the planet & will fall forever, orbiting the earth.

Answer 3

The force of gravity is called weight (W). And, according to Newton's universal gravity law W = GmM/R^2; where m is your mass, M is a planet's mass (Earth or the Moon), and R is the distance between the centers of the two masses.

So, from the equation, you can see that if M(moon) < M(earth), which it is, so that M(moon)/M(earth) < 1.00 and you are the same distance (R) from their respective centers when you hop on the scale to weigh yourself, you would find W(moon) = W(earth)(M(moon)/M(earth)) so that W(moon) < W(earth) since M(moon)/M(earth) < 1.00

Notice that if r < R; where r is the radius standing on the Moon's surface to weigh and R is the radius standing on the Earth's surface to weigh, the smaller Moon's radius between centers of mass will tend to raise the weight on the Moon. But the smaller radius is not sufficient to make your Moon weight greater than your Earth weight. In fact, W(moon) ~ 1/6 W(earth); so you'd be 30 pounds on the Moon if you were 180 pounds on Earth.

As to the satellite...it stays up there because of something called centrifugal force, which is equal and opposite in direction from weight. As a satellite revolves around Earth at velocity v, the force of gravity (weight) keeps tugging at it toward the center of Earth's mass. But that tug changes the direction of the velocity, which wants to go straight out into space. Any change in velocity (either its magnitude or direction) creates an acceleration. And whenever there is acceleration acting on a mass (e.g., the satellite), there will be a force = F = ma; where m is mass and a is that acceleration.

In the case of the satellite, that force acts outward away from the center of the Earth because that's the direction of the acceleration. In fact, we can show that a = v^2/R, where v is that velocity that keeps changing direction because of gravity. R is the distance of the satellite from the center (not surface) of the Earth.

Anyway, satellites do not fall down on earth because that force F = W, the weight of the satellite. So the net force on the satellite f = F - W = 0 = ma; which means a = 0 and the satellite (m) neither flys out into space nor crashes into the ground because it's acceleration is zero.

Answer 4

The earth has a lot more mass than the moon, the more mass the stronger the gravitational field.
Satellites do not fall to earth, they are designed to stay in orbit. Perhaps you mean meteorites, if so, they are fall in space as meteors and some of them are drawn to earth by gravity, when that happens they fall and may burn up in our atmosphere.

Answer 5

hey! you weigh more on the earth than on the moon due to gravity. You see on earth the gravitational field strength is around 9.81 newtons per kg, however on the moon there is hardly any gravity.
Weight = mass x gravitational fieldstrength
so if the gravity is lower (i.e. on the moon) the weight will be less. NB - the mass stays the same no matter where you are.
Hope this helps.... dont know how much detail you wanted....

Answer 6

on earth acceleration due to gravity is about 9.8m/s^2 but on moon it's 1/6th of earth so w=mg u know it as 'g' is more on earth so weight is more on earth.

satelites revolve arround planet in a orbital
path means in a elliptical path so the gravitational force is balanced by centripetal force.so satelite doesn't fall by the gravity

Answer 7

2.the satelite is turning aroung earth with a certain speed
this speed prevents it from falling and turning in the correct direction
(it has to do with the normal acceleration)
1. weight is equal to mass times gravity our mass is cte but gravity on earth is so much stronger than that on the moon