2
votes
1answer
381 views

What is the buoyant and viscous force acting on a ball in free fall?

I was thinking about a situation were I have a long cylindrical jar with some viscous liquid in it. I also have a spherical ball with me. I drop the ball into the liquid inside the jar with some ...
-3
votes
1answer
90 views

What is the physics behind this invention? [duplicate]

Could someone explain the physics behind this US patent ? The apparatus is supposed to generate electric energy from gravity. The idea of the invention is to use a trapdoor kind of mechanism to push ...
5
votes
2answers
3k views

Why do helium filled balloons move away from the Earth?

From my understanding objects do not fall but are pulled to the earth from gravity. With this in mind, I can't understand why if helium filled balloons are not pulled by gravity then shouldn't they ...