2-for-1 Special!!! Space-Time

Space-time is kind of a big deal. As we discussed in class, when distorted by matter (massive bodies like planets, moons, etc.), it creates the sense of gravity. Earth's gravititational tug-of-war with the moon in turn is responsible for causing the Earth's tides. Gravity also causes light to bend, streeeeeetching our perception of time.

Don't worry!....both concepts take awhile to get one's head around. Here's your assignment:

Watch the video (to the right) about space-time AND watch the full animation about tides (http://www.onr.navy.mil/focus/ocean/motion/tides1.htm) -- the total viewing time is less than 5 minutes. Then post a SPECIFIC question you have about EACH concept that you want answered in class.
(That means two questions from everyone. Oh, and by the way, "I don't get space-time?" doesn't count as a good, specific question!) ;)

We'll discuss your questions in class during our next meeting and get to the bottom of these topics.

Centri-WHAT?!

We've discussed two new forces recently that aren't actually "new" or "forces." Centrifugal "force" is your perception of inertia/momentum's effect on you when going in a circle -- there's no actual force pushing you outwards.
Centripetal force isn't a "new" force at all, but simply a description of whatever happens to be holding something in its circular motion -- gravity, tension, air pressure, etc.

Riddle me this, what is the cetripetal-type force that allows a car to go around a turn rather than flying off in a straight line? Briefly explain why/how the force acts in a centripetal ("center-seeking") manner.

Hint: What matters most is where the rubber meets the road.