Physics 10 Momentum and Impulse (27 of 30) 2-D Collision Ex.1

In this video I will find velocity final of a 2-dimensional collision, example 1.

[edwardgilbert]

I love you videos, they have helped me a lot in my school, in fact this video helped me proved a test question was worded wrong.

[matthewstone]

I missed a day of my hs ap physics course that explained a way how to get both final velocities after a collision like this and I couldn't get help on it and there is a test later today. This video just saved my grade. Thank you so much

[ahmadelwi]

I hate physics and you don't make me love it; but you DO make it easier to learn. Thanks!

[bardiashahrestani]

Professor van Biezen, I'm sure all of us have who have watched your videos can agree on one thing: You are a life-saver!
I just want to say how much I appreciate but it just truly won't fit in a comment.

[zebamahmud]

Thank you so much. You teach so much better than my actual university teacher who fails to make me understand anything. you're the reason I'm hopefully going to do good in my physics mid-term, thanks.

[Dractonis]

This is the sort of whiteboard you'd look at and cry because it's literally just a foreign language of alien symbols. Yet it makes perfect sense now, in 11 minutes, after reading 30 pages of blabbing in my course book. Brilliant and thank you from the UK.

[MichelvanBiezen]

Yukelele

The angle after collision, depends on the angle of impact, not  on the size of the balls.

[mb-faze]

Hmm, for a perfectly elastic collision, theta1 + theta2 should add to 90 degrees. So the fact that they don't in this example means that the collision is not perfectly elastic and therefore kinetic energy is not being conserved (kinetic energy will have been converted to deformation heat, noise or friction). Would have been interesting to calculate this loss in kinetic energy.

[msenyk]

this is how physics should be taught, thank you.

[nicholasgalliano]

Thank you so much for making this clear. Now I can incorporate the formulas into my programming code. However, I have one question - if the initial velocity is 10m/s, my own logic dictates that the sum of the velocities of both projectiles should add up to 10m/s. If I add the two velocities (5.18m/s + 7.32m/s), I get 12.5m/s, which is 2.5m/s over the initial velocity before the collision. Not sure if I'm thinking this right, I'm very new to this sort of thing

[sigmablueforce]

The title must be corrected to inelastic collision because the problem and its solution in this video are all about momentum conservation.
In elastic collision, the conservation of momentum and kinetic energy must apply.
The professor did not take into account kinetic energy conservation.

[Mathemusician]

Stumbled upon this video purely by accident, and I just so happen to have a problem which is exactly the same to this with different numbers. Thank you for explaining it. I understood it perfectly.

[barrymckockiner]

Had the same question with different numbers on my homework. You saved me man

[johnthefisherman]

Thanks, this was a great help to me for my class. When I play pool, I do not have to go through all of this, though!!!

[ef]

Prof. I am getting a different answer. Can you tell me what I did wrong, please? 
I turned 10=v1fcos(30) + v2fcos(45) into [(10-v2fcos(45))/cos(30)]=v1f . 
Then I plugged it into 0= v1f sin(30) + v2f sin (45) and I got that V2f=-19.32m/s and V1f= 27.32m/s.
I even did a system of equations on my calculator with v2f=y and v1f=x and I got the same results. I traced back everything and I cannot see where I went wrong. Even when I simplify the equations to decimals as you do in the video, so long as I substitute v1f into the 0=.... equation, I get the same answer, PLEASE HELP!!! Love your videos by the way.

[PhysicalSciences]

Amazing lesson, and a big help for preparing my own. Thank you!

[wessbl]

Took me a month to solve but I finally got it thanks to your help.

[michellearosemena]

thank you sooo much, you've saved my life

[jh]

Great vid. watched several. HOWEVER, Would love to of seen a video of a combo of linear momentum and angular momentum together in a collision in such that a pool ball is moving at a given velocity; WITH a rotation of a given rad/sec backspin, colliding with another ball. Using alpha, and w(omega) in angles while using the P momentum system. I been assigned several of these in my classes this semester and can't find videos.
Thx and keep up the great vids.

[identity]

if the two masses are the same, shouldn't the angle between them be 90 degrees instead of 75 degrees?