Running

Watching Breaking Bad, I realized there were two periodic table elements on the title. Are they significant in making meth?

When I hold my finger on the screen , it shakes. WHen I type, a ton of other keys come up, so if I press One letter a random string of letters follow, occasionally I'll encounter a random click outside the keyboard when I type. At least autocorrect helps lol...

I am typing this from my phone while riding in a car on a bumpy rd. is the screen on a iPhone 4S linked to the gyroscope? If it is, how do I turn it off? I only have this problem on bumpy. Roads; the touchscreenk works fine anywhere else

I like going on Wikipedia from time to time to brush up my scientific knowledge a bit. However, there's one mathematical sign I keep running into that I've never learned about: it's like an integral sign, with a circle in the middle. What's that supposed to do? What level of math is that usually introduced in?

The gear ratios on my bike are bad, so I either want to replace some gears or put new ones on. What steps would I have to go through to accomplish this?

For a school project, I'm making a solenoid cannon that can launch a tennis ball. I'm doing this by wrapping coils around a PVC pipe big enough for the ball. Since the ball is non-magnetic, I figure I'll have a magnetic projectile behind the ball that pushes it, treating the ball as a load. I'm thinking the power source for my solenoid will be multiple 6-volt batteries wired in series.

So, question 1: should this projectile be a bar magnet, or is it okay to use a non-magnetized ferrous material?

I already have a set length for the canon, and I also know what the velocity of the ball needs to be when exiting the canon. Knowing these factors, I can easily calculate the magnitude of force needed inside the solenoid.

For question 2, what kind of formula can I use to find the amount of current/coils I need in my solenoid to get my required force?

Bonus question: Do you have any more advice for my project?

At a local museum, there is an interactive exhibit where kids can release two disks simultaneously; one goes down a linear ramp, and the other a sinusoidal. Both ramps start at the exact same height, and end at the same height as each other. Due to the law of conservation of energy, to my understanding, both disks should have the same velocity. However, the disk on the sinusoidal track wins the race by a few seconds. What causes

this?

Don't be afraid to add calculus and/or physics terms in your answer if necessary

While driving my '97 Ford Taurus, I noticed that I had to press my brakes almost to the floor to get it to stop. Checked the brake fluid and it was low, so I poured more in. The problem continued, so I checked the fluid again after a few days passed, and the master cylinder was still full.

I took off both of my front tires and checked the calipers, they seemed alright. The pads are almost brand new (replaced them about a month ago). I checked for leaks, there weren't any. I'm stumped. Unless I hit the brake pedal quickly, my foot has to go almost to the floor. When I hit the brake quickly, the brakes work like they normally should (I don't have to press as far).

Any ideas what could be wrong with the brakes, and what happened to the missing fluid?

I have a reasonable background in chemistry and physics, and I know what a combustion reaction is, but nobody has ever told me how we end up with a red/yellow/blue/green/whatever glow that seems to radiate ABOVE a burning material, instead of the material itself glowing.

This part is irrelevant, but I figured I'd add that the first result for categorizing this question was under Sports > Hockey. Just... dafuq?

Magnetism:

-Gauss

-Tesla

Circular Motion:

-angular velocity

-angular momentum

It may be subtle, but there has to be some kind of subconscious favor to one of these.

I'm preparing for the AP physics exams, but here's the twist: I'm not taking the class. Everything I've been doing to prepare for this test has been independent, and I need all the resources available to me. I've been in the library and been through a couple books, and I've been on collegeboard.org, but that's about it. Are there web sites and/or online resources that can help me prepare?

I'm currently enrolled in Calculus 2, to give a bit of info on my math background.

For my science background... I've gone all the way through the highest level of physics my high school has to offer, but that only adds up to about 3/4 of the stuff on the Physics B exam. I'm pretty proficient in chemistry, but I doubt that matters much for AP physics.

I keep getting that dreaded response through chat: the word "yeah." How can I reply to that?

I'm on Chrome right now and have already tried clearing the cache, and also looked for any bad plugins. Is there anything else I could do to get my browser back up to the speed it used to have?

At home I found a great series of educational videos that can really help my preparation for the AP physics exams in the spring, but I can't access these videos at school because a Barracuda filter blocks all youtube videos. All the proxies I've tried are blocked, so I'm turning to Y!A for help. What are a couple good proxies, or even more helpful, what is a site that has videos not linked to youtube?