Physics170

Consider what happens when you jump up in the air. Which of the followings is the most correct?                                                                                  

A; It is the upward force exerted by the ground that pushes you up, but this force can never exceed your weight.                                                

B; When you jump up the earth exerts a force F₁ on you and you exert a force F₂ on the earth. You go up because F₁ > F₂.                      

C;   Since the ground is stationary, it cannot exert the upward force necessary to propel you into the air. Instead, it is the internal forces of your muscles acting on your body itself that propels the body into the air             

D; You are able to spring up because the earth exerts a force upward on you that is stronger than the downward force you exert on the earth.

E; When you push down on the earth with a force greater than your weight, the earth will push back with the same magnitude force and thus propel you into the air.

    Which one is right and why?

I guess is B, if F2 were greater than F1, you would stand still and kick the earth's butt (im ok at economics, physics... basic school stuff and that was long ago)

I think that the answer is E!

Process of elimination:

A is wrong because the force the earth pushes up on you when you are standing still is equal to your weight.  When you push down on the earth, you are adding more force to your original weight.  Therefore, the earth will push back with a force greater than your weight (Newton's Laws..  equal and opposite reaction..).

B is wrong, again, because of Newton's Laws.  Each opposite force is equal.

C is wrong because the ground does exert a force up on you...  I think.

D is wrong because it is a restatemend of B.

E is correct!!!  It is also the opposite of A.

I might be wrong!!  I am only four days into Physics...

What you say about D and B is true, dunno which one is (dont really care as long as i can jump), but the elimination process looks great! hehe

The correct answer is E.  A, B, and D all contradict newton's 3rd law, and C is just total bullshit.

DONT DISS C!!!!!!!!! 

I think its C because it stands for COOL!!!!!

Just kidding its probably E since majority RULES!!!!!!!!!!!!

Go with E. For every action there is an equal and opisite action, or something like that. Since the earth is so much bigger than you, it's movement is un detectable.

B ofc. If F1=F2 then you would just remain stationary. So F1>F2 so B is correct.