Simple g Force questions (1 Viewer)

[wb47]

A rocket accelerates upwards from the surface of the earth at 3ms^-2
An astronaut of mass 80kg is strapped on to a seat in the rocket.

a) What is the upwards force exerted by the chair on the astronaut?

F = ma
F = 80 x 3 = 240N

c) What is the resultant force acting on the astronaut?

F = X - mg
F = 1024 (worked out in part b) - 80 x 9.8 = 240N

I think I'm wrong could someone correct me please?

Thank You.

 

[romesh]

This is a strange question- I don't understand why the resulting force acting on the astronaut is different to the upwards force exerted by the chair. Why? Because when the rocket is sitting on the ground, the chair is already exerting an upwards force of mg (reaction force of gravity). So the upwards force exerted by the chair when the rocket is accelerating would be mg + ma with a = 3. This would be why the astronaut feels a g-force > 1. That would be 1024N- so what was the question in part b?

 

[wb47]

part b was determine the apparent weight which i calculated to be 1024 N (mg + ma)

thanks

 

[jamesfirst]

Im guessing bcos weight force will counteract the exerted forcr is the reason why resultant will be diff