Can someone explain g on earth

In summary, the acceleration due to gravity on Earth is approximately 10 m/s^2. The distance traveled by an object dropped from rest in the 3rd second is 30 meters, and the equation to calculate g at a given altitude is g at h = g at sea level * (r Earth / (r Earth + altitude))^2. Alternatively, g at 100km can be calculated using the equation g = (G*m1*m2) / r2.
  • #1
jsm6252
13
0
my question leads to something bigger but to start g force on Earth is 9.8m/s2 for simlicity let's say 10.

1-is it rite to say if you drop an object in the 1st sec its acceleration is 10m/s2 in the 2nd sec it's 100m/s then in the 3rd sec it's 10000 m/s
2-if the above is correct what is the distance traveled i.e in the 3rd sec has the object traveled a total of 10000m.
3-how do you calculate g 100km above the earth.
 
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  • #2
jsm6252 said:
1-is it rite to say if you drop an object in the 1st sec its acceleration is 10m/s2 in the 2nd sec it's 100m/s then in the 3rd sec it's 10000 m/s

No. After one second, its velocity is 10 m/s, after two seconds its velocity is 20 m/s, after three seconds its velocity is 30 m/s, etc. Its acceleration remains constant at 10 m/s^2.
 
  • #3
To calculate g at 100km you need to use the equation:

g = (G*m1*m2) / r2

Where G is the gravitational constant, m1 is the mass of the earth, m2 is the mass of the body currently at 100km, r2 is the distance from the centre of the Earth (Earth's radius plus altitude of 100km).
 
  • #4
thank you
 
  • #5
A quicker way to calculate g at a given altitude h is to use the relation:

g at h = g at sea level * (r Earth / (r Earth + altitude))^2

where r Earth = average radius of the earth.

The quantity G * m1 * m2 / r^2 is the gravitational force acting between two masses m1 and m2 which are a distance r apart.
 

1. What is the value of g on Earth?

The value of g on Earth is approximately 9.8 meters per second squared (m/s²). This is a constant acceleration due to gravity that is caused by the Earth's mass and the distance from its center.

2. How is g measured on Earth?

G is typically measured using a device called a gravimeter, which measures the acceleration of gravity at a given location. This can also be calculated using the mass and radius of the Earth.

3. Why is g different on other planets?

The value of g on other planets is different because it is dependent on the mass and radius of the planet. Planets with larger masses or larger radii will have a stronger gravitational force, resulting in a higher value of g. Additionally, the rotation and composition of a planet can also affect the value of g.

4. How does g affect objects on Earth?

G affects objects on Earth by causing them to accelerate towards the center of the Earth. This is why objects fall towards the ground and also why objects have weight. The value of g also determines how much force is required to lift objects off the ground.

5. Can g change on Earth?

Yes, the value of g can change on Earth due to factors such as changes in the Earth's rotation, tides, and elevation. However, these changes are very small and are not noticeable to humans. The overall value of g on Earth remains relatively constant.

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