Responding 2 years late lol.... I'm glad to hear someone thought my southern dialect still qualifies as English :)

Glad I helped. Sounds like you had a pretty special teacher in 7th grade. If we find one teacher that actually cares if we learn or not, then we've done pretty good. The "good ones" always want you to come where they are, so that you may go further. Glad you passed. Now go be amazing!

Glad to help :)

I'm just happy to help. Keep Learning!

frrrrrrr

You can take the boy outa Alabama, but you can't take Alabama outa the boy. Thanks for watching!

in the back ground i'm hearing the eighties song "i need a hero" playing. No joke i'm about to youtube it now lol. glad it helped.

you are very welcome :)

It's been 6 years have you found the answer?

roll tide lol

you are welcome :)

sweet home Alabama lol. thanks :)

I would settle for better than average, but thank you :)

9 Years old and a little long winded, but here it is my friend: kzfaq.info/get/bejne/rbiTg898ksjXoKs.html The example I work the second vehicle has an initial v of zero is the only difference.

elastic = no loss of energy, inelastic = loss of energy

You would have to know the type of friction, but of course, if the friction acts.... the collision is no longer elastic.

This reply is too late to help, but no no no. Said in the spirit of an upset toddler lol.

@@turdfurg67 In your first example i noticed that m2 is twice as large as m1. Would it not be possible to write it at such, and thereby allowing the masses to cancel out on both sides?

@@illinnear7233 I remember once in college when I found a better solution to a problem and pointed it out to my professor, "You could do it that way mister, but some of us came here to work today". Seems better to cut down a student than to admit you had a brain fart. Good job :) It would be much much simpler math.

you are toooooo kind :)

You've said nothing egregious. I guess 6 years later looking back is I should have explained the reasoning, but I think in other older videos I had done that. The relative velocities are not our concern, but the conservation of momentum, so the initial momentum consisted of +0.030 kgm/s and -0.100 kgm/s. SO the initial momentum of the system is -0.070 kgm/s, which means the final is as well. Focusing on the momentum should have been a focus on the conservation, but a youtuber had just asked me to solve a problem like that, so I kept it as straight forward as I could.

@@turdfurg67 Thanks for answering. I should have specified that the reason I asked this question is because I thought there could be a way to simplify the problem by assuming one ball has an initial speed of 0 and the other has an initial speed of 8 (or -8) but I guess it wouldn't really simplify anything because at the end we would still have to convert the answer because the frame of reference isn't the same? Or it wouldn't work at all because both balls don't have the same mass? I am just curious.

Thank you

I needed someone to feed (Was that song reference reply too obscure in 2021?)

think of it as a number line. since this is one dimensional the 8 ball is going in the chosen negative direction.

The cinetic energy conserves. So Ec1 = Ec2 and you will get something like m1(v1i^2 - v1f^2) = m2 (v2f^2-v2i^2), and you divide that with mv1i + mv2i = mv1f + mv2f which is also m1 (v1i - v1f) = m2 (v2f - v2i) and....you will get that :D=

AlbOuse Banana oh, thanks!

in 4 hours fr

you're welcome and your teacher is ice cold. I don't because it makes no difference in the formula. I would argue with my teacher that the dimensional analysis still works, so I should not be deducted. Since the equation is basically mv=mv, then its basically a glorified proportion, so the units come out in the wash (excuse my alabama slang). If I was solving a problem of a Hydrogen nucleus, then I sure would not want to use 1.67 x 10^-27 kg, I would use 1 amu. If it hit helium then m1= 1 amu and m2=4amu. Mean teachers man, stop making physics ugly... That would be a good t-shirt.

Algebra, move the 5 to the other side to make V alone

0 initial momentum = 0 final momentum (v*m = momentum)

As in both have negative velocities, but one overtakes the other? The formulas are all the same. All that changes are the values you substitute into the equations.

It's derived from conservation of energy. There's another video on my channel where I derive it.

just separating it from the variables before final division.

we may have derived the special equation from using KE, but we are working with momentum and must maintain the vector nature. Forgetting (+) and (-) is the number one reason students miss points on these. I would teach you to always use your signs and in the advent of it being a scalar like work or energy, then it would eventually square itself out and become positive through calculations.

If one final velocity is given then you just need the conservation of momentum equation. plug and chug the answer. Let me know if you're still stuck.

I'd help but I'm 2 months behind checking comments. sorry.

Sorry, I'm late on this one. You can do basic mv + mv problems without conversion because the units cancel out. That being said, if you want to do impulse or energy calculations then you must change everything to kg. It's just a lot of problems are just looking for velocity, so say for example it was a helium nucleus and a hydrogen nucleus colliding, then you could use 4 amu and 1 amu in the mv + mv portion and still come out correct and save you from using their x10^-27 kg actual values.

I can handle that. Someone once said I sounded like Landry Clark from Friday Night Lights.

WHen they have the same mass it's beautiful. You still use the two equations in the video, but when you substitute them together all that happens if you prove the two particle exchange velocities. So if object 1 had a velocity of +2 m/s, then the final velocity of object 2 is +2 m/s. I'd add a picture, but youtube hasn't got there yet :(

​@@turdfurg67 could you pls type up the the equations because I think I must be messing up... when I cancel out the masses nothing makes sense anymore to me :( On multiple choice I can just memorize that they exchange velocities but for free response questions I am screwed

@@tsariza kzfaq.info/get/bejne/hs-na8eAmquyo3U.html Just for you. Good luck on free response!

@@turdfurg67 omg I love you 😭

You left the signs out of your calculations, which are vital to vector calculations. You also missed a decimal on the 0.3. The difference in momentum sums is 1, and that's because for the sake of instruction I did not keep decimals to thousands place. Thanks for watching and don't forget the directions. Also on the positive, even if I would have goofed which over 10 years has happened many times, at least there were no irritating adds to watch.

@@turdfurg67 u right, sorry

@@NowisFurther it's all good. Thanks again for watching.

thanks?