Physics Lesson: Pulley Systems Part 1 Dynamics for High School

[Klegend1000]

can you teach me about the equations and stuff? I havent really reached highschool yet

[Atadavidl]

You taught me more in 5 mins than my physics teacher could in 1 week. AP Physics B lifesaver

[pfvc95]

Thank you so much!

[seragreen]

is there a video where you explain how to calculate the total net force acting on a system?

[TerminatorToast]

Isn't the acceleration of the system 3.27m/s^2?

The answer you got (.33 m/s^2) is the answer I got (3.27 m/s^2) divided by gravity (9.8 m/s^2).

Is there any reason you did this? Please respond I'm so confused!

My work:

10g-5g=15a

98N-49N=15(kg)a(m/s^2)

49N/15(kg)=a(m/s^2)

a=3.27m/s^2

[YOSICKBRO]

@TerminatorToast you're right, I saw the same thing. They didn't multiply by acceleration of gravity which they should have done, they just left it as 5g for some reason

[PatrickVedlog]

Why is it 5/15? I can't really understand.

[Bakugantsuvai1]

@PatrickVedlog It is simple the formula for acceleration is g(m2-m1)/(m2+m1)

[PatrickVedlog]

@Bakugantsuvai1 What is g? g as in Fg(Gravity)?

[Bakugantsuvai1]

@PatrickVedlog You are in the correct track now when solving for acceleration make sure you subtract the bigger mass from the smaller one on the numerator. The denominator, however it does not natter which mass you add first as long both masses are positive. Oh yes I should tell you this formula only works for the pulley system in the video. (Where there is no friction and the two masses are hanging. I hope that I helped you out.

[PatrickVedlog]

@Bakugantsuvai1 It did! And I already knew that it only works for the pully system. But thanks! I really appreciate your help. :)

[Bakugantsuvai1]

@PatrickVedlog You are very welcome, these days physics teachers do a very terrible job in teaching this subject hence I needed to look up these videos to help me understand and remember these concepts (which meant I needed to teach myself from scratch).

[PatrickVedlog]

@Bakugantsuvai1 Hahaha! I understand. As I said. Thank you very much again :)

[Bakugantsuvai1]

@PatrickVedlog You should watch every video of this channel if you have time so you can be ahead of your friends lol so you can be more sharper than your classmates. I even got interested in projectile motion as for your question. I have trouble explaining to people but I think the 9.80 is from acceleration due to gravity. In addition when he calculates the tension force after you solve for acceleration you can plug the numbers in any equation.

[PatrickVedlog]

@Bakugantsuvai1 Alright.. I think I got it. But yes, I really love physics and I'm planing to become a particle physicist. Now as I am at the first year of High School, science have become more fun and interesting! Now my classmates are studying just basic math.

[Bakugantsuvai1]

@PatrickVedlog Very funny, my teacher teaches so poorly that I only get B's in the class so I hope to boost myself to an A wish me luck. By the way only basic math? Our teacher is going to makes us do projectile motion next one of my favorite subjects in physics.I find that my textbook does a terrible job of ordering the chapters in the book.

[PatrickVedlog]

@Bakugantsuvai1 Here in Norway, we start with physics and such the second year of High school. We have like Math, English, Norwegian, Science and such. But not deeper into science. That's for next year. Hopefully, next year I'm studying in London. Oh! I didn't ask. What grade are you in? Good luck friend!

[Bakugantsuvai1]

@PatrickVedlog Since I am uncomfortable telling you my grade in school all I can tell you is that I am nearing high school graduation. In my country right now we do not start physics until around second year of high school which really stinks because the honors science kids start doing this stuff in 5th year of primary school. So I asked my primary school teacher if I can go into science honors and she said I will not succeed in the course such outrage

[PatrickVedlog]

@Bakugantsuvai1 Alright. So much like here. I am OK for you not telling me, because the "uncomfortableism" just so that's said. :) I respect you very much. Thank you for all your help and I wish you the very best luck at the rest of your life! :)

[PatrickVedlog]

@Bakugantsuvai1 But! Only one question. When he calculates the N. Why is it T=5.9,8? Where does he get the 9,8 from?

[TheMisterApple]

Can anyone tell me why he added the two equations? My teacher never taught us that. I have a dynamics test coming up in two days, and I really realy really need help.

[dramione1996]

this was good, but I feel like I'm still going to fail my test tomorrow...I just don't LIKE physics!

[TheBrightBeat]

The thing that confuses me the most is making the whole system within the boundary right away instead of splitting it up into two and that is the way my teacher prefers. :( but this definitely helped me to realize how you set it up!

[Melvel22]

Actually he is right, its (5/15)(9.8)

[Melvel22]

He said oops its supposed to be 0.33

[heiboo810]

5/15g = 3.3 m/s^2?? How come?

[0oWaterNgo0]

@heiboo810 if i'm not wrong.. he is taking g = 10m/s^2.. therefore 5/15g = 3.3m/s^2

[rip111buddy]

thanks a LOTTT !!! i was about to fail in projectile and pulleys !

[mcaruana1]

@rip111buddy Thanks for letting us know. Glad we could help.

[yellopanda]

omfucking god, Mr. Galifinakas thank you so much, i thought you were an idiot after watching you in the hangover but your actually very bright young man <3

[PhysicsEH]

@yellopanda I never noticed the resemblance. I'll bug him about it.

[WanderleiCornell]

thanks brah

[PhysicsEH]

@WanderleiCornell Glad to help.

[MiturBinlsderty]

the chalkboard and chalk writing looks so clean lol!

[PhysicsEH]

@MiturBinlsderty That took lots of practice and we washed the board between takes. Thanks for noticing.

[Famousx81]

@physics EH, thanks for the detailed response. Sorry, I forgot abt acceleration due to gravity. Thanks, again.

[Famousx81]

Shouldn't acceleration be .33m/s^2? Thanks

[PhysicsEH]

@Famousx81 You can simplify the calculation by saying Fg on the 10kg (=100N) is pulling one way and Fg on the 5kg (= 50N) is pulling the other way. So 100N one way and 50N the other way means there is 100-50 = 50N pulling in the direction it will move. So Fnet = 50N. Fnet = ma and the total mass being moved is 15kg, sub in the numbers 50 = 15a and you get a=3.3 This confirms our original answer. I hope this helps.

[InterplayDesigns]

thanksss

[PhysicsEH]

@InterplayDesigns Glad to help.

[SuCKeRPunCH187]

@PhysicsEH shouldnt the tension vector of the 5Kg mass in the FBD be longer than its Fg component?

[PhysicsEH]

@SuCKeRPunCH187 You have a good eye. It should be longer! We missed that. Thanks.

[selo2010]

Thanks anyway :D

[selo2010]

can you do one whit the W angular speed and whit the diametre of the pulley D whitout numbers only letters

[PhysicsEH]

@selo2010 HI. Sorry to take so long to get back to you. We are not at school at this time so we are not making any videos right now. I also don't do this type of problem in my course so unfortunately we don't have any plans to do this type. I hope the other videos were some help to you even if we did not do the particular one you needed.