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~christina~
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Homework Statement
One scheduled activities during a shuttle misison was the launching of a communications satellite. This 1220kg satellite Geo II is a uniform cylinder of diameter d= 1.18m and length L= 1.72m. It is identical in mass, density, and shape to Geo I, which is already in geosynchronous orbit around the earth. Prior to launching, a motor inside the shuttle bay takes one minute to set the satellite spinning from rest to 1.46 rev/s about the cylinder's axis. At this instance the spinning satellite is released from the bay compartment and placed in the same orbit as Geo I. GeoI has zero moment of inertia.
a) what force must the motor exert on the satellite to obtain this angular speed?
state your assumptions.
b) Before it's release, what is the magnitude of the linear velocity of a point on the curved surface of Geo II ?
c) what is the anglular displacement of Geo II before it's release?
d) Do the 2 satellites have the same total energy once Geo II is in orbit?
If yes, use physics principles to explain why. If not calculate the difference in total energies.
e) what are the linear and angular momenta of Geo I as ikt orbits about the Earth's center?
f) What is the gravitational potential energy of Geo I in this orgit?
[NOTE: treat the Earth and the satellites as isolated bodies. Disregard frictional or drag forces]
http://img145.imageshack.us/img145/8650/38926826zx6.th.jpg
Homework Equations
[tex] \sum W = 1/2 I \omega_f^2 - 1/2 I\omega_i^2 [/tex]
[tex] s= r \theta [/tex]
[tex] v= r\omega [/tex]
[tex] a_t = r \alpha [/tex]
The Attempt at a Solution
a) Um not sure about this at all.
I know:
[tex]m_2= 1220kg [/tex]
diameter= 1.18m
radius = 1/2 (1.18m)= .59m
Length= 1.72m
[tex] \omega_i = 0 rad/s [/tex]
[tex] \omega_f= 1.46 rev/s[/tex]
I guess I'd have to convert the angular acceleration first to rad/s
[tex] \omega_f= 1.46 rev/s[/tex]
[tex] 1.46 rev/s (2\pi rad/ 1 rev ) = 9.17 rad/s [/tex]
[tex] \omega_f= 9.17 rad/s [/tex]
a) what force must the motor exert on satellite to obtain this angular speed?
state assumptions...
well I was thinking of using this equation but I don't have the distance traveled unless I guess I consider that it is rad/s
[tex] \sum W = 1/2 I \omega_f^2 - 1/2 I\omega_i^2 [/tex]
and I don't have I either...
I need help on this.
Thank you
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