Physics Doubt -

Question

It is said that we we are in free fall then we are weightless, but isn't weight W=mg or F=GMm/R^2, so while falling we would have mass and would be accelerating, and also would have a height from the centre of the Earth, so, can you please explain how we are weightless when in free fall?

Answer 1

Now here's a good question for you. Knowing the acceleration of gravity at the Earth's surface, and assuming that the Earth is an even density throughout (which it isn't!), if you had a vacuum-filled tube through the center of the Earth and you dropped yourself down it, how fast would you be travelling as you pass through the exact center of the Earth? (assume radius = 6.37*10^6 m). (neglect frictional forces with tube walls!)

-- Cheers, -Mr. d.

Answer 2

We feel weightless when in free fall. You are right that as long as we are on Earth (or near Earth's surface) we have the Force of gravity as W=mg acting on us, but when standing still on Earth we feel Weight because of the Normal Force of the ground pushing back on us. So when we are in free fall the gravity is still pulling us towards the center of the earth but since we don't experience the resistance force we feel weightless even though we aren't.