Esacpe speed - energy required

[confused200]

Homework Statement

A space probe is launched from the equator in the direction of the north pole of the Earth. During launch the energy given to the probe of mass m is

E=(3GMm/R)

Deduce that the Space probe will not be able to travel into deep space

Homework Equations

Minimum KE needed = - GMm/R

The Attempt at a Solution

I said that if minimum KE was as above then having three times that would mean that it would escape but the answer is that it won't so I'm puzzled? How do I deduce that it won't escape if it has 3 times the energy E=(3GMm/R)

 

[confused200]

Should it have a negative sign in front of it, I remember something bout infinity? Please help!

Homework Statement

A space probe is launched from the equator in the direction of the north pole of the Earth. During launch the energy given to the probe of mass m is

E=(3GMm/R)

Deduce that the Space probe will not be able to travel into deep space

Homework Equations

Minimum KE needed = - GMm/R

The Attempt at a Solution

I said that if minimum KE was as above then having three times that would mean that it would escape but the answer is that it won't so I'm puzzled? How do I deduce that it won't escape if it has 3 times the energy E=(3GMm/R)

 

[BruceW]

hmm. You're right, that the probe should be able to completely escape from the Earth's gravitational field... Maybe you are also supposed to take into account the gravitational field from the sun?...