(a) Suppose a projectile is launched vertically from the surfacer = R of the earth with in...

(a) Suppose a projectile is launched vertically from the surfacer = R of the earth with initial velocity where k2 = 2GM. Then solve the differential equation dr/dt = k/ (from Eq. (23) in this section) explicitly to deduce that r(t) → ∞ as t → ∞.

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(b) If the projectile is launched vertically with initial velocity v0 > , deduce that

Why does it again follow that r(t) → ∞ as t → ∞?