What Should You Use for a Gravity Demo?
Let’s say I want to make a demonstration of the universal law of gravity. This law says that there is an attractive gravitational force between ANY two objects with mass. We can calculate the magnitude of this force as:
In this expression, m_A and m_B are the masses of the two objects. The distance between their centers is r and G is the universal gravitational constant with a value of 6.67 x 10^-11 N*m²/kg² (which is super tiny). This force is so tiny, you can only measure it when one of the objects is super massive (like the Earth).
There was this video I saw that showed the changed in measured mass of a piece of lead when another larger sphere was placed under it. I thought that was awesome, but according to my calculations — it wouldn’t work.
So, I thought about it. This video demo looks super old. Maybe I can repeat this with a better balance and actually get it to work.
