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EK Physics
Started by IlyaR
mv^2/r = force of gravity, as you said.
as the explanation says, set them equal:
mv^2/r = G mM/r^2 - m= satellite, M=planet
v^2 = G M/r
see, the mass of the satellite is gone?
as the explanation says, set them equal:
mv^2/r = G mM/r^2 - m= satellite, M=planet
v^2 = G M/r
see, the mass of the satellite is gone?
^ Easy to see derivation.
I like to tackle these problems intuitively.
If I increase the the string between my center of rotation and a mass on the other end, it'll take more time for rotation.
I know in centripetal rotation, increasing the length of my string would mean DECREASING my ATTRACTIVE force Fg.
Already, I see A is the trick to this type of question. What is responsible for Attractive force? GMm/R^2. Aka Masses of Both Planets and radius between them. Orbital radius is a product of mv^2/r and I eliminate it. I want to focus on my attractive force.
From there, I see that a decrease in mass is the only way to decrease the attractive force between two objects and C is the answer.
Not gonna lie, I chose D because I didn't consider F=Gmm/R^2 and the inverse relationship between attractive force and radius between two bodies. My mistake, hopefully won't do it again.
It seems like a convoluted explanation, but I blanked on Gmm equation so I resorted to the centripetal force side of things. I find that type of theoretical knowledge helps in panicky situations. Stay calm and carry on.
I like to tackle these problems intuitively.
If I increase the the string between my center of rotation and a mass on the other end, it'll take more time for rotation.
I know in centripetal rotation, increasing the length of my string would mean DECREASING my ATTRACTIVE force Fg.
Already, I see A is the trick to this type of question. What is responsible for Attractive force? GMm/R^2. Aka Masses of Both Planets and radius between them. Orbital radius is a product of mv^2/r and I eliminate it. I want to focus on my attractive force.
From there, I see that a decrease in mass is the only way to decrease the attractive force between two objects and C is the answer.
Not gonna lie, I chose D because I didn't consider F=Gmm/R^2 and the inverse relationship between attractive force and radius between two bodies. My mistake, hopefully won't do it again.
It seems like a convoluted explanation, but I blanked on Gmm equation so I resorted to the centripetal force side of things. I find that type of theoretical knowledge helps in panicky situations. Stay calm and carry on.
