Earth's Rotational Velocity Question (1 Viewer)

[Aerath]

 

[Dumbledore]

i think its a... cause the earth does spin from west to east and you do add the velocities since the reference point is not the moving launch point but rather the fixed point centre of the earth
v= 2pi(r)/t ~=465m/s
its not a major enough difference so that if 1 orbits the other won't though

EDIT: the velocity boost will be largest on the equator though and it doesn't say the launch point on the earth

 

[k02033]

my answer would be (d)

lets forget gravity for a second, if we launch a satelite with velocity relative to earth =5 ms^-1, then that satellite will travel relative to the earth with 5ms^-1, this is completely independent of the earth's velocity. (when u throw a ball at 5 ms^-1, you will see the ball travel at 5ms^-1, end of story, you dont factor in the fact that the ground under you is orbiting the sun at some velocity.)
so for the question, if u launch the satellite with either -Vo or Vo relative to the earth, then the earth will see the satellite going at velocity with magnitudes sqrt(Gm/r) regardless of its own velocity and satellites will orbit, but what is different is the velocity of the satellite relative to the sun, ie satellite will have (Velocity relative to sun) =Vrelative to earth +V earth relative to sun.
so east satellite will have (Velocity relative to sun) = Vo+V earth relative to sun.
while west satellite will have (Velocity relative to sun) = -Vo+V earth relative to sun.

so if we wanted the satellites to orbit the sun, then launching it west or east matters.

 

[Dumbledore]

ok i'm probably wrong cause that Ko guy is pro at physics, but i wasn't talking about the velocity the earth is travelling relative to the sun but rather the fact the the earth spins, if the reference frame is with respect the the centre of the earth the fact that the earth rotates should still make a difference to the velocity, only if the reference point is with respect to the launch point it won't make a difference.

 

[helper]

The answer is A

We aren't provided with the initial velocity or energy, so we don't know it will obtain orbit.

 

[k02033]

i was wrong (d) is not right.. i misread "earth's rotational velocity" to be "earth's orbital velocity" and i dont know why i assumed the satellites were launched with velocity with magnitude Vo relative to earth hahah silly me

 

[starkskyy]

isn't the orbital velocity only affected by the distance between the satellite and the planet? (according the Kepler's 3rd law)

sorry for digging this thread back up. just curious.

 

[youngminii]

Orbital velocity = sqrt(GM/r)
ie. it is affected by the mass of the planet and the distance between.

 

[kaz1]

My naswer is B as Satelite A is assisted by the rotaional velocity of the earth. It cannot be A as orbital velocity isn't influenced by Earth's rotaional velocity as far as I know. It cannot be C as Satelite B is not assisted and the Physics pro eliminated D.

 

[youngminii]

The answer is A

We aren't provided with the initial velocity or energy, so we don't know it will obtain orbit.

I agree with this.