OPENING QUESTIONS: Pick a rocky planet or dwarf planet somewhere in our solar system. Look up the particulars and determine the acceleration due to gravity on that object. Then please calculate your weight there if your mass is 75 kg.
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LEARNING OBJECTIVES:
I will be able to apply Newton's theory of gravitation to orbits during today's class.
WORDS O' THE DAY:
- Centripetal ("towards the center")
Centrifugal("away from center")- Gravitational Constant: G = 6.674 × 10-11 Nm2/kg2
- Period ("Time for one revolution")
FORMULAE OBJECTUS:
- v2/r: centripetal acceleration
- mv2/r: centripetal force
- Fg = Gm1m2/r2: This is Newton's famous equation for gravitational attraction.
WORK O' THE DAY:
Work with your team to see how far you can get in deriving Kepler's Law of Periods using Newton's Law of Gravity in 10 minutes!
GO!
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Finish up these problems!
Problem #3: The Juno space probe is in a (not very circular) orbit around the great planet Jupiter. If we ignore that and just say that the orbit is circular and the probe is moving at .1056 miles/sec, how far above Jupiter's cloud tops is the Juno probe? (note: in turns out this value is much too small. If you're interested, go ahead and google "orbital speed of the juno probe" and Google will confidently spit out this value. It just turns out to be inaccurate. Go Figger)
Next clockwise person leads:
Be careful with your data on this one...
Problem #4) The solar system (literally: the stellar system containing the star named 'sol') is about 26,000 light years from the center of the Milky Way galaxy.
How fast are we orbiting around the galactic center? (Hint: The source of the force....Hint Hint: Assume ALL the mass in our solar system is concentrated in the sun, in other words ignore all planets, comets etc... Also assume all the mass of the galaxy is clustered at the Galactic Center. Considering the size of the black hole that resides there that isn't' quite as big a leap as you might think)
(It turns out there's a recent discovery that makes this a tad sketchy, but we'll talk about that during our closing).