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.

 

 

The Power of Rube!!!

Reuben Goldberg was an American cartoonist who's wild cartoons showed crazy contraptions doing simple tasks. His cartoons have since inspired countless people to challenge their creativity and their understanding of physics in the real-life production of simple yet complex machines. Fun, imagination, and physics are key.

The simple pattern

ENERGY -- FORCE -- ENERGY -- FORCE -- ENERGY -- FORCE -- ENERGY.......

Start by reviewing the week 6 notes online (this is a mandatory part of the assignment).



Watch the large video (to the right) and find examples for the following six concepts. BE SPECIFIC and briefly explain why your examples demonstrate the concepts.

Static Friction
Kinetic Friction
Work
Gravitational Potential Energy
Elastic Potential Energy

Kinetic Energy

Phun Physics with Phelines!

Hope you all are cat lovers. I've always been more of a dog person, but there was no video called "Dun Dysics with Dogs." Watch the video (at right) and share something you learned from it? Be detailed and accurate in your response...."I learned about friction" isn't the kind of response we're striving for. You all did a fantastic job with your responses on the last blog post -- keep up the great work!

:) Mr. R

Grounded for Life!!

Let's say that someone you know is driving WAY too fast on the freeway (obviously, you personally are much too smart to do anything so foolhardy and dangerous!). Ultimately, your friend's parents will find out he's driving at 80 mph no matter what. He can't escape getting busted! BUT, from the options below, choose which POV/frame of reference he would want his parents to have so his velocity seems the lowest relative to them.

Choose one by voting in the poll to the right, and add a comment to explain WHY your choice is best...

The parents driving 60 mph toward him (on the other side of the freeway, of course).
The parents driving 60 mph in the same direction on his side of the freeway.
The parents sitting along the freeway watching him drive by. (External)

Let it Fly!...in 2 Dimensions☺

By playing we learn. So, let's play. On the left side of the blog is a link to a game called "Bazooki: A Silent Affair" and it's all about 2D projectile motion. Play the game for at least 10 minutes, and BE OBSERVANT while you play. Mess around with different angles and different amounts of force, and look at how it affects the flight path of the projectile and the distance it covers.

After you've played, post a reply of something you learned/observed about 2D projectile motion. Talk about vectors (horizontal versus vertical), force, or angles -- or all three!

Make sure to complete this tonight. Have a great one, and I'll see you soon. :)

Mr. R

Acceleration....Getting You Up to Speed

Thanks to our outstanding demonstrators (Astin, Ben, "Scant!" & Dr. Hogan ) -- and to some clever engineering by Casio -- we were able to get three cool shots of a ball dropping.

So, what does it mean to ACCELERATE?! There are several different points of the ball's location in each image. In your own words, respond to the two following questions:
1. What's different about the ball's velocity in at each point where it appears in the image?
2. Why is there more distance between each point where the ball appears in the image?
(Show me that you understand the concepts of velocity and acceleration by being detailed in your response!)

 

Let's start by...

....taking a deep breath. In all likelihood, you've heard things about taking physics. Maybe scary things. Let me tell you this loudly, clearly, and from the get go.... physics isn't hard.

Ok, that statement might be a little misleading, but the point is that physics doesn't have to be hard. That's my approach. We're going to be learning what I like to call "practical physics." You know, learning about why things work and act the way they do. We'll throw in some of the essential math (you can't have physics without math; that's like having music without notes), but this won't be a course in number crunching. We'll be doing things "hands-on," creating full-scale demonstrations/experiments, gathering our own data, and do all that in order to identify the laws and forces at work in our world.

So, welcome to a year of learning and investigation together. And let me emphasize the word "together." Learning is a two-way street. I'll do my job, but it's up to you to carry your end of the bargain. Engage in the learning, ask questions, be a team player, and follow through on the handful of responsibilities thrown your way. That's what makes good teamwork and that's what makes good learning.

Let's do it.

I Hate to Sound Dense, but...

As with light, so with sound. Well, not always, but there are a few parallels, and one of those parallels is speed. The material (or medium) that sound passes through affects its speed. How so?

For a benchmark, let's use the speed of sound in air at the beach in Malibu on sunny, 70-degree day -- 1,125 feet/sec (666 mph), also known as Mach 1.

How will the speed of a given sound change (FASTER, SLOWER, NO CHANGE) in the following scenarios:

...on top of Mount Everest?

...submerged in a pool?

...through a wall?

...in Florida (same air temperature, at sea leavel, much more humid)?

...in space?

Excluding space, pick the option above that you think will transmit sound waves fastest, and explain WHY.

It Takes Two to Tango -- Pressure & Heat

Having watched the Mythbusters, Adam & Jaimie, release the full force of a PRESSURIZED WATER HEATER on a runway overlooking San Francisco, there clearly exists a link between heat and pressure. But what is it?....That's my question to you.

How are pressure and heat related and dependent on one another? Give me some "for example"s.

Be reasonably thorough in your explanation, which should be at least a couple of GOOD sentences long.

(BTW i think that sentences like this 1 r beneath u and that u should take the time to present ur best work. in other words show better punctuation capitalization and care in the work u produce and ur written communications. just like we established at the beginning of the year i will start taking off points for poor sentences on ur blog work as well as ur quiz responses. better find that "shift" key! if ur still reading good for u b/c to get full credit on this assignment u need to include a smiley face (a colon & parentheses r fine) in ur blog response. ☺

My Brain has a Mind of Its Own!

Just like we talked about in class, our brain does a lot that we're not aware of to make sense of the constant stream of sensory input it receives. Watch the video and participate in it (best in full screen mode), and READ the whole article (it's short!) describing the phenomenon.

http://games.yahoo.com/blogs/plugged-in/video-optical-illusion-wins-head-191105551.html

Crazy, right?! For your reply, since I can't ask a follow-up question specific to this topic, all you have to do is briefly state 1. something nice that someone did for you today and 2. something nice you did for someone else today.

If you can't think of anything for #2, the day isn't over, so go practice a random act of kindness, no matter how small. ☺ Cool beans!