Gravity question, I need others to see if I might have an answer

[AtomStorm]

Question: Why do two things with different masses fall at the same time when dropped from different heights?

 

**if its already been answered don't read unless u want to really hear what i have to say.If you can explain the answer in the comments**

 

Before i go on I'm not anywhere near college I wondered about this question and I thought of all the things I've learned on gravity and its not a lot. I may not use the correct terms for the answer.

 

My answer: Since the earth is huge and massive it has a higher amount of force pushing on itself but its not just the earth every object must have some amount of force pushing itself. The two objects I'm going to use as example is a 2 ton weight bar and a tennis ball. The way we thought, before this question was asked, was since the weight bar is heavier it should fall first and when i mean heavier it get get pulled by the earth stronger that the ball. But there is another force that's keeping the bar from winning it force that it exerts on the earth. Since all objects have their own gravity the bar also has it own gravity that pushes itself upward and slows it down. Now the tennis ball while being attracted slower than the bar its gravity is less that the bar drastically.Therefore the tennis ball doesn't have much force stopping it ending the race with a tie.

[Strange]

Question: Why do two things with different masses fall at the same time when dropped from different heights?

 

1. Why is this in "Science News"?

 

2. What do you mean by "at the same time"? Do you mean, hit the ground at the same time? If so, they don't. Galileo's famous experiment involved two objects dropped from the same height. Regardless of their different masses, they will fall at the same rate, and reach the ground at the same time.

 

If they are dropped from different heights, then the object dropped from the greater height will take longer to reach the ground. Again, regardless of the weight.

 

Your explanation for this is overcomplicated. You just need two things:

 

1. the force on the object caused by gravity, which is proportional to its mass (from Newton's law of gravitation)

 

2. The rate of acceleration due to a given force is inversely proportional to its mass (from Newton's second law of motion)

 

Therefore the mass cancels and the rate of acceleration is proportional to the force, independent of the mass of the object.

 

https://en.wikipedia.org/wiki/Newton's_law_of_universal_gravitation

http://csep10.phys.utk.edu/astr161/lect/history/newton3laws.html

[math]\displaystyle f = G \frac{m M}{r^2}[/math]

(where m is the mass of the object and M is the mass of the Earth).

 

[math]f = ma[/math]

 

Therefore:

[math]ma = G \frac{m M}{r^2}[/math]

 

Cancelling m:

[math]a = G \frac{M}{r^2}[/math]

 

Therefore, acceleration just depends on G (gravitational constant), the mass of the Earth, and its radius.

 

[ACG52]

Since all objects have their own gravity the bar also has it own gravity that pushes itself upward and slows it down.

Gravity does not push upward. Gravity is only attractive.

Edited November 1, 2015 by ACG52

[Ophiolite]

Strange and AGC52 have pointed out the weaknesses in your explanation. However, you are to be complimented on exploring your current understanding of the topic prior to a formal study of it. Please view their corrections in a positive light and take their observations on board.

[AtomStorm]

Thanks for helping me out guys