Space/Projectile Motion/Centrifugal Force (1 Viewer)

[Brodie-B]

Hey. Need help pretty desperately on this question:

Explain using projectile motion and centrifugal force why the Apollo 13 crew only felt weightlessness after the finish of the launch burn even though they were still inside the Earth’s gravitational field.

Any help will be greatly appreciated.

 

[Dragonmaster262]

Strange question; how does projectile motion and centrifugal force relate to weightlessness? I think this has something to do with g-forces but I'm not sure just what.

 

[Brodie-B]

Yeah i could explain it using g-forces, but I have no idea where to go with this...

 

[helper]

I would ask the person who wrote the question what they mean by centrifugal force.

 

[adomad]

when orbiting around earth, you are continously falling towards earth, but at the same time, the earth is curving away from you. since you are free falling, there is no resultant force hence you don't feel weight.

in terms of projectiles and centrifugal force, i guess you could say that projectile motion says that you are falling down at a=-9.8( acts inwards) and since you are in circular motion, the centrifugal force (acting outwards) cancel out?

never seen a question like that before... but that is my shot at it..

 

[Brodie-B]

that actually makes sense... i didnt think of it like that. Thanks.

 

[adomad]

welcome, but don't quote me because im not sure if that will get you full marks for that question.

 

[Dx_God]

Explain using projectile motion and centrifugal force why the Apollo 13 crew only felt weightlessness after the finish of the launch burn even though they were still inside the Earth’s gravitational field.

where did u get this question lol? first of all centrifugal force does not exist... it's believed to exist because of lack of centripetal force which lead to object's tendency to fall outwards. secondly, of course the crew are still inside earth's gravitational field or else they would have to be at infinity.

anyways back to the question. now the key to answering this question is CENTRIFUGAL FORCE (LACK OF CENTRIPETAL FORCE) and ur CURVATURE (trajectory or ur projectile motion). as i already explained earlier, if u can't provide the centripetal force then the object will fall outwards. now this centripetal force is directly proportional to ur tangential velocity. earth's gravitional attraction is fixed at a constant distance from earth but however ur centripetal force is not. meaning once ur tangential velocity is larger than ur orbital velocity, the centripetal force is larger than ur gravity itself and causing the shuttle to fall outwards. at that moment, the crew will feel weightless. another situation that the crew will feel weightless is if ur tangential velocity is much less than ur orbital velocity, causing the centripetal force to be less than ur gravity and causing the shuttle to fall to the direction of earth. at that moment ur crew will also feel weightless (how weightless u will feel is dependent upon the difference between ur tangential velocity and ur orbital velocity l Vt-Vo l eg. abit less than orbital velocity will still make u feel ur weight (less though) but no orbital velocity will cause u to undergo freefall and feel complete weightless). hopefully my hypothesis is correct but i can't guarantee u that it's 100% correct and hopefully my answer helped.