What Would Happen If Earth's Attraction Suddenly Stopped?

[vissh]

hello :D
Neglect the effect of rotation of the earth. Suppose the Earth suddenly stops to attract objects placed near its surface. A person standing on the surface of the Earth will
<a>fly up <b> slip along the surface <c> fly along a tangent to Earth's surface <d> remains standing

Initially, Normal force, N will be acting upward and mg downward. Resulting F_net=0 [Object at equilibrium]
So, when the Earth suddenly stops to attract ,mg vanishes But N should be present at that instant And thus the person should fly up :)

But the book gives ans is <d>
What you think ^.^

 

[The legend]

what is your reasoning that the Normal reaction acts?

 

[vissh]

hmm my reason is -
You agree with me that when Earth was attracting, Normal force, N and mg were acting and also they were canceling each other ,for equilibrium.
Now,At the moment just [when Earth stops attracting],mg will vanish .But at that very moment I think "N' will still be there and cause body to fly.
So what you think friend! ^.^

 

[The legend]

i meant to ask "why" does the normal reaction act?
Does it have to do anything with the way the body presses on the ground?

And yes, I agree that when Earth was attracting, Normal force, N and mg were acting and also they were canceling each other ,for equilibrium.

 

[vissh]

Yep Normal rxn act as the body presses ground. Hmm at the instant [when Earth stops attracting] , the ground maybe somewhat pressed and the normal rxn should be there at that instant.
:)

 

[The legend]

the ground maybe somewhat pressed and the normal rxn should be there at that instant.
:)

Ah, here's where you go wrong...i think

There's nothing as "somewhat pressed" here actually. (no elasticity involved for it to remain pressed and all, we neglect such things)

There, it should be fine for you now.

 

[vissh]

OKzz :D Thanks Legend ^.^

 

[The legend]

You'r welcome.