Ok Sup Forums, I need help with my physics homework. Btw, this is all in metric so americans...

Ok Sup Forums, I need help with my physics homework. Btw, this is all in metric so americans, don't try to help me if you don't know metric.

I'll post my calculations in another post in this thread.

Btw, spring constant is 0.285 N per cm.

Bump 1. M8s, plz help

Bump 2

Bump 3

You fucking moron just apply the formula you were given during the lesson. This is notebook question should be readily available in your book. Open it from the relevant page and feed the numbers in.

Download wolfram alpha

This is for a lab I did, there is no text book to get the answers from.

I've gotten to the point that I have the acceleration, however when I apply

Vf^2 = Vi^2 + 2a * delta of distance

I constantly get 0.

That would be too easy.

is that free

It is, but again, too easy.

You have the mass of the elastic right? Use the conservation of energy. 1/2 kx^2 = mgh. Do everything in meters

most physics classes are in metric, even in USA.

Thanks, based user. Thought I could try and do it through Kinematics.

make the assumption that the spring interferes with itself and goes to 0.

It says to state all assumptions.

Initial velocity is nonzero. You need to calculate the spring's potential energy when stretched to the given distance, then assume that all that energy becomes kinetic and solve for v. Use that as initial velocity and apply the formula for constant-acceleration kinematics, x=x0+v0t+(at^2)/2, where a is g and x0 is 0.

21

Now factor in the delta of the material elasticity, negating its modulus, as Newton-metres/cubic metre.
Remember to reverse the sign on the Ti factor when you introduce Maxwell-Watt's Law of Inelastic Compression, before you integrate.

Hope this helps...

If you can do problems via energy instead of kinematics, it's easier like 99% of the time. In this case, the elastic changes its force as it relaxes, which constantly changes the acceleration. The normal kinematic equations are only built to handle constant acceleration. Cheers

Kek

also, don't forget about 6th derivation

Mr. Palmers class using that hard OP

Isn't*

Ok, now I have pic related through energetics. Can someone verify if I got it right?

Just assume you're in a vacuum with no gravity and say infinity.

I don't see why this has to be hard.

You have to convert the centimeters to inches, it would be easier that way.

Now I know that's bullshit.

Meters=miles, and h=hydrogen, so the answer is 6.

Even if that's right, you should be ashamed of your handwriting.

the elastic will go 1074 meters? you think that's right?

i get about 26.5cm

> american scientists dont use SI

Its the scientific standard you retard. A scientist anywhere uses SI.

Iit's would fucking help you but you don't want Americans... dumb ass... all physics is converted to the metric system even in America. Learn about what you say before you rule people out

My physics knowledge is basic, but isnt the integral of velocity = position? Wouldnt you be able to integrate the earlier equation to get an equation in terms of position?

Also think energies

Spring PE before release = gravity PE at peak.

Grav PE = mgh
Spring PE = kx^2/2

F=ma
V(x) = max + vo
Y(x) = 1/2max^2 + vox + xo
Y(x)= 1/2*(0.25/1000)*1.223*x^2 + 0 - 4.3/100
Find where Y(x) = 0

Do:
spring energy = potential energy.
1/2 * k * x^2 = m*g*h

k = feather constant
x = the length of how far the feather is stretched (or in this case elastic)
m = mass
g = gravity constant
h = height

>solve for height
h = (1/2 * k * x^2)/(m*g)

works because of the conservation of energy.
In reality it will reach less height than that, because some energy is lost from stuff like air friction, which generates warmth.

Didn't even read thread btw, I see you already have the answer, OP.

no need for energies.

You have Force to get acceleration, initial velocity, and initial position.

He's right, you know.

OP here.
Yea. I'm pretty retarded. Anyways, fixed my units and the answer is 10.74 m (sig digs makes it 11m due to 4.3 cm in energetics).

Verify, anyone?

Yep

and you're not taking into account gravitational acceleration on the way up.

You're comparing the spring PE to the gravitational PE of simply dropping it.

Thanks for the physics help Sup Forums.
I didn't know if I should have gone to /sci/ cause I don't know if they're anal about this or not.

Adios!

no

If that's really the mass of the object everything is right

Yea, mass was declared as 0.25 grams at the beginning.

/sci/ doesn't take homework requests Sup Forumsro

Use fractions or SI prefixes for your values, all those decimals must be a pain to write, especially in more complicated stuff in the future.
Like, what the fuck is 0.00025kg, just write 0.25g or 250mg.

Also, in physics you should only use 2 more decimals after the values that you have.
Your smallest value is 4.3cm, not 4.30cm, which is 1 decimal.
Round your result to something reasonable like 10.74m.
Writing 10.743425076m is not only an eyesore, but also false, because your input values are not measures as accurate that you could predit the result with this extreme level of accuracy.
And 10.74m is correct.

gravity is in m*g*h included.
It does not matter how fast or at which way it gets to the height h that's how potential energy works.
You know, if I hadn't taken into account the gravitational acceleration on the way up, then it would fly for fucking ever beacuse it would never slow down.

OP here.
0.00025 kg is used because I had to use kg in m*g*h.

I just write what I put into my calculator. I know thats weird, but meh.

And with sig digs included the actual answer is 11m. Two sig digs. Check it.

I don't know which calculator you use, but they all have a button that shorts prefixes.
On my Casio calculator, there is a button with the label (x10^x).
pic related is how you use it.
hit 5, hit that button, type 9. Now you got a 5 with 9 zeroes.
for "milli-" you use x10 -3
for pico you use (whatever) x10 -9.
Are do you plan to type 0.000000001264 when you calculate stuff like picoFarad for example?
Better get used to it sooner than later.
Just write everything with prefixes, and enter everything into the calculator with prefixes. You can even set the result to display with prefixes. Nothing you can do wrong anymore, like writing a zero too much or too little.

hey dumbass ALL PHYSICS IS IN METRIC
t.an american taking physics courses

You are overthinking it. The answer is 5. The answer is always 5. Or 42.

Pic related, another example. Let's say you calculate gravity or some shit and use earth's mass in the calculation. As even google shows correctly, you use *10^x to short it.
In the calculator you'd enter 5.972 (*10^)24 where the bracket term is a single button shortcut.
You wouldn't enter 5972000000000000000000000.

a fucking kilometer? What fucking elastics do you have in Eurostan?

No it's not. We can do both but we still use English units here as well