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naeblis
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Q: In the absenceof air resistance, the least speed with which a body must be projected vertically upward from the Earth's surface if it is to reach an altitude of 800km is...
800km = 8.00x10^5 m
radius of Earth = 6.37x10^6 m
mass of Earth = 5.99x10^24 kg
Kf +Uf = Ki + Ui
0 + 0 = 1/2 mv^2 + (- G Me m / Re + 800km )
1/2 mv^2 = G Me m / Re +800km
m drops out
v = square root of [ (2)(6.67x10^-11)(5.99x10^24)/(7.17x10^6) ]
v = 1.06x10^4 m/s
is this right? thanks in advance for the help
800km = 8.00x10^5 m
radius of Earth = 6.37x10^6 m
mass of Earth = 5.99x10^24 kg
Kf +Uf = Ki + Ui
0 + 0 = 1/2 mv^2 + (- G Me m / Re + 800km )
1/2 mv^2 = G Me m / Re +800km
m drops out
v = square root of [ (2)(6.67x10^-11)(5.99x10^24)/(7.17x10^6) ]
v = 1.06x10^4 m/s
is this right? thanks in advance for the help