Doesn't work out logically

[kenhung123]

When a person is in a rocket accelerating upwards with the same magnitude as gravity but of course in the opposite direction. That means they feel heavier by showing Fn>Fg


Lets say the mass of the person is 50kg and g=10
So:
Fnet=Fg+Fn
ma=Fg+Fn
50x10=50x-10+Fn

Fn=1000N

Now in order for us to 'feel' weightless that means we need the Fn=0 for that to happen, we need ma=Fg in order for them to cancel out e.g. 500=500+Fn (same magnitude and direction) Fn=0 how is this possible? To travel in opposite direction but then in theory it is in the same direction?

[/0]

implies , which implies .

I.e, your acceleration is free-fall acceleration. In this case you feel no normal force.

[kenhung123]

But what about when you feel weightless in a rocket moving upwards and you are still in the gravitational field

[/0]

You don't feel weightless in a rocket moving upwards. You feel weightless in a rocket free-falling downwards.

[kenhung123]

Hmm then how do astronauts float whilst still in the gravitational field when still in space?

[Cthulhu]

Hmm then how do astronauts float whilst still in the gravitational field when still in space?

They are in free fall around the earth and their only acceleration is due to gravity.


http://en.wikipedia.org/wiki/Free_fall

[kenhung123]

Thanks!