Anatanoshi

I think i got it.

Thank you!

Recently i learned about Quadratic Inequallities and i can't understand when i should flip the > or < sign.

Can anyone help me with that?

 

Do you know how Newton's motion equations are derived?

 

If you have object at time t0 (we can simplify it's t=0) at location x0 (also we can simplify it's x0=0),

then it moves at time t1 to location x1,

then it moves at time t2 to location x2.

 

We can create equation describing this movement, to predict:

1) whether it's constant velocity (lack of acceleration, linear equation),

2) whether it's accelerating, or whether it's decelerating.

 

1) Movement with constant velocity equation will look like:

f(t)=x0+v*t

where v is in meters per second m/s:

v= (x1-x0)/(t1-t0) = (x2-x1)/(t2-t1) = dx/dt

 

2) Movement with acceleration/deceleration equation will look:

f(t)=x0 + (a*t^2)/2

 

a = (v1-v0)/(t1-t0) = ( (x2-x1)/dt - (x1-x0)/dt ) / dt = dv/dt

Acceleration/deceleration is change of velocity in unit of time. Velocity has already unit m/s. After further division by time in seconds, you get m/s^2.

If velocity remain constant. There is no acceleration or deceleration.

This was very helpful thank you!

 

If you divide acceleration on the surface of some cosmic object by Earth's surface gravity acceleration, you receive dimensionless fraction or multiply of g.

1.62 m/s^2 / 9.81 m/s^2 = 0.165

 

It tells how much weaker or stronger is gravitation relative to Earth.

 

Similar like if you divide distance from some planet by distance from Sun to Earth, ~ 150 mln km,

you receive distance in A.U. (Astronomical Units).

1 AU = ~ 150 mln km

Why are we squaring the m/s?

And the purpose of g is to check how much force acts on an object like in the formula for height energy? (Eh = m * g *h)

1.6g would be stronger than Earth's gravitation.

 

"Surface gravity 1.62 m/s2 (0.1654 g)"

https://en.wikipedia.org/wiki/Moon

 

What's the diffrence between m/s2 and g?

You're searching for tidal locking.

https://en.wikipedia.org/wiki/Tidal_locking

 

Thank you.

Earth orbits itself as well as the sun due to its own gravity (if i remember correctly).

The moon has less gravity (i think its 1.6g) but it still has gravity.

So why doesn't the moon rotate like Earth but a bit slower?

Even if we could cure cancer easily i doubt we'll be able to live more than 1000 years...

There will always be another illness that will pose a problem to us.

I've been trying to learn from HyperPhysics but i don't get most of what i read.

I have almost no scientific knowledge...

 

I would start from learning what are elementary particles, pair production of matter and antimatter, and further annihilation of matter and antimatter.

Then go to fusion, and isotopes, and periodic table. How one isotope can be transformed to another isotope, another element.

Are those in there?

Can't find them.

Try HyperPhysics

http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html

 

+1 for healthy and honest interest in how Universe is working.

Looks like a great website thank you!

Any suggestions on where to start?

Hello, i'm a 9th grader from israel.

There aren't many science classes in my school and i'd like to know more about science (mostly Physics or space related stuff).

Last week i found this forum and i've learned ouite a few new things, but i want to start learning specific areas in physics first.

Where should i start?

And if you know a simple written site that i can use to teach myself i'll be glad to know about it.

I'm not a scientist but i'd like to know more about physics.

Can someone explain or direct me to a site with a simple explanation about String Theory?

Thanks.

The dopler effect is what makes objects far away seem smaller or sound weaker.

Can anyone explain the science behind it?

Thanks!

From what i understand those time crystals can move by themselves.

So why are they called "Time" crystals?

Also what matter can turn into a time crystals?

Everything experiences time, if someone doesnt experience time wouldnt that make him non-existent?

How would not experiencing time even feel like? Would i just feel like im standing in place?

Or is there just no possible way to even think about that?

So if we somehow invent a machine than can travel faster than light will we be able to travel forward in time?

Hello, i like space related topics and i've been looking for an answer to a question i thought of.

Can time feel faster for some creatures or in some places in the universe?

Is the rumor about a year for a human is seven years for a dog true?

Thanks.