changing orbits

Identity · 2009-01-14 02:34:18

Sorry this isn't really a math question

A shuttle orbiting the earth at 400km deploys a satellite of mass 800kg into orbit a further 200km from earth. Calculate the work that must be done by the shuttle to deploy the sattelite.

Thanks

JaneFairfax · 2009-01-14 03:10:55

Identity · 2009-01-14 10:45:45

Thanks Jane. The solutions have

as the answer though... do you think it is wrong?

Also I tried to work this out using the difference in kinetic energy since

:

But I get a different answer! Isn't

?

Last edited by Identity (2009-01-14 10:53:13)

JaneFairfax · 2009-01-14 11:05:25

I made a mistake. My working was for bring a stationary object from 400 km to 600 km. If the objects need to be in orbit around the Earth, then their kinetic energy may have to be taken into account as well. Oops.

Identity · 2009-01-15 01:50:11

Sorry Jane, I don't really understand how to combine kinetic energy with potential energy in an equation. Do I just sum up the energies after and subtract the sum of the energies before?

No matter what I try I can't seem to get

!

Last edited by Identity (2009-01-15 01:53:53)

luca-deltodesco · 2009-01-15 03:45:22

from circular motion equations:

(just me checking the equation you had was correct)

then potential energy:

the change in energy from increasing it's orbit then is the combination of the change in potential, and the change in kinetic

i'm really stumped how to get the answer they want

Last edited by luca-deltodesco (2009-01-15 03:51:57)

Identity · 2009-01-15 03:53:11

Thanks a heap luca, I guess they probably typo-ed the power of ten

Math Is Fun Forum

#1 2009-01-14 02:34:18

changing orbits

#2 2009-01-14 03:10:55

Re: changing orbits

#3 2009-01-14 10:45:45

Re: changing orbits

#4 2009-01-14 11:05:25

Re: changing orbits

#5 2009-01-15 01:50:11

Re: changing orbits

#6 2009-01-15 03:45:22

Re: changing orbits

#7 2009-01-15 03:53:11

Re: changing orbits

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