Question

If a projectile is launched vertically from the Earth with a speed equal to the escape speed, how far from the Earth's center is it when its speed is 1/9 of the escape speed?

Answer 1

v=sqrt(2•G•M•R)
v1 = v/9 = sqrt(2•G•M•R)/9,
r =81•R = 81•6.4•10^6 m =5.18•10^8 m

Answer 2

5.16*10^8 for Mastering Physics