Answer:
a.)r=4RE/4
b.)r=2RE
c.)ZERO
Explanation:
a.) given v= 0.462 which is V= 0.466Ve
Since the projectile is shot directly away from earth surface the speed it escape with;
v=√2GM/RE......................eqn(1)
M is the Earth's Mass
RE is the Radius
From the Law of conservation of Energy
K+U=0...............................eqn(2)
K₁+U₁=K₂+U₂....................eqn(3)
where K₁ and U₁ is initial kinetic and potential energy
K₂ and U₂ are final kinetic and potential energy
Kinetic Energy (K.E) decrease with time as the projectile moves up and there is decrease in Potential Energy (P.E) , it will let to a point where K.E will turn to zero i.e K₂=0
U₂=K₁U₂ ..........................eqn(3)
From Gravitational Law
U₁= -GMm/RE ..................(5)
U₂= -GMm/r .....................(6)
Where "r" is the distance
v= 0.462√2GM/RE
v= √GM/2RE
GM/4RE - GM/RE = -GM/r
r= 4RE/3
b.) "r" is calculated by this equation;
K₁=0.466
K₁= 1/4MVe².............................eqn(9)
substitute eqn(1) into eqn (9) then
1/4m2GM/RE=0.466GM/2Re
GM/2RE - GM/RE =-GM/r
r=2RE
c.)The potential energy and kinetic energy is the same in terms of their size both in different directions, while the potential energy face outward, the kinetic energy face inward therefore the least initial mechanical energy
required at launch if the projectle is to escape is ZERO
