How Fast to Launch an Object from Mercury for a Final Speed of 3000 m/s?

[ohheytai]

The radius of Mercury (from the center to just above the atmosphere) is 2440 km (2440x10^3 m), and its mass is 0.3x10^24 kg. An object is launched straight up from just above the atmosphere of Mercury.

(a) What initial speed is needed so that when the object is far from Mercury its final speed is 3000 m/s?

Homework Equations

vi² = vf² + GM/ri

The Attempt at a Solution

i got 4151.8315 m/s
and its wrong help me please!

 

[Redbelly98]

Homework Equations

vi² = vf² + GM/ri

The kinetic energy of an object is (1/2)mv². Do you see what is missing in your formula?

The Attempt at a Solution

i got 4151.8315 m/s
and its wrong help me please!