shreyasshree

like Swami Vivekanda said, : Show me!

I am in no position to answer your question scientifically but out of some experience in sports I can tell you that warming up is extremely vital to your stretching. You don't need to warm up for long but little is advisable. For example you could start by mobility exercise; like rotating your arms and torso. If you like you could just jog around or if you prefer you could do it on spot. Warm muscles are much more easily stretched than cold ones, always warm up first to get blood circulating throughout the body and into the muscles. A warm-up should be slow and pleasant. If you don't you might risk tearing or injuring the muscle.

Can anyone tell me some interactive websites that can help me revise my high school science and prepare for exams?

Something like khanacademy will be great!

And please don't mention any that are NOT free.

Hi Shreyasshree,

 

while QM is certainly fascinating, it's possible that you find it discouraging, or that your efforts are less rewarded than they deserve, in the case that you try to learn QM before having some background.

 

Depending on how easy you're already with this background, it would be a good idea to start with it, so that your time spent on QM (later if necessary) is more profitable and enjoyable.

 

Linear algebra (vector spaces, linear operations and all that goes with them). Fluent is needed.

 

Waves. Fluent as well. You may start with acoustics, go on with optics.

 

Signal processing is very helpful. Or antennas. Or possibly detailed knowledge of diffraction aspects in optics, but this uses to be less complete than signal processing.

 

Electromagnetism, at least some, would be useful.

 

Well, I suppose there are many different paths to learning QM. It takes years to get a somewhat clear picture of it, so you can perhaps begin with an incomplete background (...don't know what yours is) and add more elements of comprehension over time.

 

I'd suggest not to read the introductions for the general public - the ones that want the explain using analogies. These analogies simplify nothing, are confusing and misleading. Avoid as well the philosophical approaches of duality and the like, which bring only useless complexity. Don't waste time with historic introductions, because QM was long misunderstood, including by physics heroes, so don't learn their mistakes only to un-learn them. Go straight to the proper up-to-date formulation, with the maths.

So basically, I have to finish my high school science first? Or can I just learn waves, optics and EM and start off ?

Hi I am in high school and really want to learn quantum theory. Is there any way I can begin? Or do I have to finish my high school science before attempting?

Are there any free books/ courses/videos that will help me learn?

Hi, i'm new in the forum, just singed in.I was thinking of doing a nice science project next year, which i will be on the first year of High School. My main goal with this project is to exceed the limit of 14 km of altitude. I'm not an expert in this subject but i have time to learn.

Below will be the questions i have:

 

Dimensions, what would be more efficient?

 

Fuel, what should i use?

 

Basics physic(and chemistry) subjects i should know before starting.

 

Expanses, is it too expansive (not a big problem but i have to know if i'm going to spend $500 or $5000)?

 

Launch site, where would be a good place to launch it (a desert or something?)?

 

 

I'm really a beginner so anything you can tell me that will help me with this will be very useful, but please understand that what i'm trying to do is greater than that bottle rockets.

 

P.s: Sorry for any mistakes i make, English is not my native language. And please don't judge me , i'm just a guy with an idea.

What about Kno3 + Sugar as a fuel? Will it fly that high?

I am building a rocket and need a way to predict the maximum altitude. Can someone send me some links or explanation?

Also, is there any way to measure the thrust of the rocket?

Thnx in advance.

The first thing to understand is that from the frame of reference of the person in the lift, there is no difference between the acceleration of the lift and gravity - both are accelerations.

 

The second thing to keep in mind is that acceleration (including gravity) is a vector. The signs change because the direction component of that vector changed.

Yeah ! I got it today! Thnx. Conformed that what i thought was kind of right!

The book says:

The lift is at rest---> weight=mg

The lift is moving up or down with uniform velocity---> weight=mg

I understood this far.

Now, it says that when the lift is accelerating uniformly

a)upwards--->weight=m(g+a)

b)downwards--->weight=m(g-a)

My problem is: Why is it + in a) and - in b)?

Thnx