Mass and weight differences on earth

In summary, the mass of an object at the Earth's center will remain constant, as mass is a property of matter that does not change unless converted to or from energy. However, the weight of an object at the Earth's center will be zero, as the gravitational attraction from all directions cancels out. This can be visualized by splitting the Earth into pieces and seeing how the gravitational forces cancel out at the center.
  • #1
mmfoley
12
0
Hello,

How do the mass and weight of an object at the Earth's center compare with their values at the Earth's surface? My textbook is pretty terrible for the non-physics major. I think they answer this question in eqations rather than plain English, so I'm having a hard time with this. Basically, I'm trying to figure out if I dug a hole down to the center of the Earth and dropped a rock down the hole, how would its mass and weight change from the surface of the Earth to the center of the earth.

Thanks!

mmfoley
 
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  • #2
Well think about conservation of mass-energy. Has anything happened to change the mass? If it did, where did the compensating mass come from or go to?

As to the weight, well that's the force of the pull of the Earth's gravity, right? How is the Earth pulling at its center? Could you quantify that? Draw some diagrams.
 
  • #3
The mass will, of course, stay the same. The weight of an object at the Earth's center is zero.
 
  • #4
Mass is a property of matter. It stays constant unless it is converted to or from energy.

Weight? Split the Earth into a number of pieces. At the centre of the earth, gravitational attraction from each piece cancels out, as the ball is attracted from all directions.
 

1. What is the difference between mass and weight on Earth?

The mass of an object refers to the amount of matter it contains, while weight is a measure of the force of gravity acting on an object. On Earth, the mass of an object remains constant, but its weight can vary depending on the strength of gravity at different locations.

2. Why is weight measured in units of force, such as pounds or newtons, while mass is measured in units of mass, such as kilograms?

This is because weight is a measure of the force of gravity, which is expressed in units of force. Mass, on the other hand, is an intrinsic property of an object and is not affected by the force of gravity. Therefore, mass is measured in units of mass.

3. How does the strength of gravity on Earth affect the weight of an object?

The strength of gravity on Earth is directly proportional to an object's weight. This means that as the strength of gravity increases, the weight of an object also increases. Similarly, as the strength of gravity decreases, the weight of an object decreases.

4. Does the mass of an object affect its weight on Earth?

Yes, the mass of an object does affect its weight on Earth. The greater the mass of an object, the greater the force of gravity acting on it, and therefore the greater its weight. This relationship is described by the formula W=mg, where W is weight, m is mass, and g is the acceleration due to gravity.

5. How do mass and weight differ on Earth compared to other planets?

Mass remains constant on all planets, as it is an intrinsic property of an object. However, weight can vary on different planets due to differences in their gravitational pull. For example, an object would weigh less on the moon because it has a weaker gravitational pull compared to Earth.

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