Mass swinging in a horizontal circle | Centripetal force and gravitation | Physics | Khan Academy

[@tunneltrance]

whoever does the teaching in this video is really good, he needs a raise

[@doni1141]

Radioactive Music 4 U I’ve been studying for days for my physics midterm and i finally realized how to use fnet=ma properly because of this video. He’s so good

[@tek1645]

Non profit organization. Donate to them if you want to help

[@frankdimeglio8216]

@@doni1141 Consider the man who IS standing on what is the Earth/ground. Touch AND feeling BLEND, AS ELECTROMAGNETISM/energy is gravity. The Earth is blue, AND the sky is blue. SO, overlay THE EYE in BALANCED RELATION to/WITH what is the Earth ! (The BLUE SKY is ALSO translucent !) GREAT. Objects fall at the SAME RATE (neglecting air resistance, of course), AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. NOW, we proceed to the next step. The stars AND PLANETS are POINTS in the night sky. Invisible AND VISIBLE SPACE in fundamental equilibrium and BALANCE IS the MIDDLE DISTANCE in/of SPACE in fundamental RELATION to the universal fact that E=mc2 is F=ma. The Earth (A PLANET) involves BALANCED electromagnetic/gravitational force/ENERGY, AS E=MC2 IS F=MA. The Earth AND the Sun are CLEARLY E=mc2 AND F=ma IN BALANCE pursuant to what is the BALANCED MIDDLE DISTANCE in/of SPACE !!! Consider what is the speed of light (c), AND consider WHAT IS THE SUN. NOW, think about what is the Earth. Importantly, outer "space" involves full inertia; AND it is fully invisible AND black ! Great. Accordingly, the Earth is in BALANCE with what is the Sun, AS the orange Sun represents what is LAVA ON BALANCE !!! Great. (Notice the role and relation of what is the EYElid.) The MIDDLE DISTANCE in/of SPACE is universally balanced to/with what is THE SUN AND the speed of light (c), AS E=MC2 IS F=MA !!! Gravity IS ELECTROMAGNETISM/energy. Notice the black space of WHAT IS THE EYE, as the stars AND PLANETS are POINTS in the night sky IN BALANCED RELATION to/WITH what is the MIDDLE DISTANCE in/of SPACE; AS E=MC2 IS F=MA !!! The FULL DISTANCE in/of SPACE is truly linked AND BALANCED to/with what is THE MIDDLE DISTANCE in/of SPACE, AS E=mc2 IS F=ma IN BALANCE !!!; AS ELECTROMAGNETISM/energy is gravity !!!!!! GREAT !!!! Notice that the viscosity of lava IS BETWEEN that of WATER AND the Earth/ground ! The orange Sun is the same size as THE EYE. Outstanding. E=mc2 IS F=ma as what is the BALANCED MIDDLE DISTANCE in/of SPACE !!!! GREAT !!! LOOK at the progression AND THE BALANCE regarding FULL DISTANCE in/of SPACE, MIDDLE DISTANCE in/of SPACE !!!, AND A POINT (ALSO c) !!! E=mc2 IS F=ma !!!, AS ELECTROMAGNETISM/energy is gravity ON BALANCE !!! GREAT !!! It ALL CLEARLY makes perfect sense. BALANCE AND completeness go hand in hand. E=mc2 is F=ma. This NECESSARILY represents, INVOLVES, AND DESCRIBES what is possible/potential AND actual IN BALANCE, AS ELECTROMAGNETISM/energy is gravity !!! Gravity IS ELECTROMAGNETISM/energy ON BALANCE !!! TIME is NECESSARILY possible/potential AND actual IN BALANCE, AS E=mc2 is F=ma; AS ELECTROMAGNETISM/energy is gravity. INDEED, TIME DILATION ultimately proves ON BALANCE that ELECTROMAGNETISM/energy is gravity; AS E=MC2 IS F=ma !!!! INSTANTANEITY is thus FUNDAMENTAL to what is the FULL and proper UNDERSTANDING of physics/physical experience, AS E=MC2 IS F=MA ON BALANCE !!!; AS ELECTROMAGNETISM/ENERGY IS GRAVITY !!! GRAVITATIONAL force/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE, AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. Gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE, AS E=mc2 IS F=MA; AS ELECTROMAGNETISM/energy is gravity. Accordingly, the rotation of WHAT IS THE MOON matches it's revolution !!! Notice what is the fully illuminated (AND setting) Moon in DIRECT comparison with what is the orange Sun !!! Again, the stars AND PLANETS are POINTS in the night sky. A given PLANET (including WHAT IS THE EARTH) sweeps out EQUAL AREAS in equal times consistent WITH/AS F=ma, E=mc2, AND what is perpetual motion, AS ELECTROMAGNETISM/energy is gravity; AS E=MC2 IS F=MA ON BALANCE !!!!!! GREAT. Gravity IS ELECTROMAGNETISM/energy, AS E=MC2 IS F=ma !!! By Frank DiMeglio

[@kaimenobeng8792]

Amazing teaching skills, very well explained.

[@anessa710]

David....I love you so much.....this concept has been hurting my brain for so long lol. but you helped me understand it! thank you! and thank you Sal!!!

[@nicholasbraud1986]

Thanks, I go back to this example quite frequently when I forget how to do these.

[@LL-kn1de]

Thank you David, you are awesome! One more question, can you make video for the question below: A playground slide is in the form of an arc of a circle that has a radius of 12 m. The maximum height of the slide is h = 4.0 m, and the ground is tangent to the circle as shown below in the figure. A 25 kg child starts from rest at the top of the slide and has a speed of 6.2 m/sec at the bottom. (a) What is the length of the slide? (b) What average frictional force acts on the child over this distance? (c) What is the normal force on the child when the child is the bottom of the slide? THANKS!!!

[@weenewman8123]

I love this guy so much.Amzing teaching skill. that next generation of sal has born.

[@hysteriodx]

ENLIGHTENED!!!!!!!

[@SuperMeatball1234]

Saved my GPA, thank you!

[@tomiwajohnson3456]

years later and this is still SO helpful, thank you so much!

[@heej8461]

Hey man, i love you

[@grantwood2955]

What if your theta is unknown and you only know that the object in motion is travelling constantly, its mass, and the radius of the circle

[@davisjohn-d6h]

Grant Wood 69 degrees to the z axis

[@xavi8780]

decompose Tension vectors and use arctan or instead use arcsin(radius/string length) to get the angle as well. I know this is 3 years late, but for those who are reading the comments right now lost I hope this helps.

[@hrn8935]

@@xavi8780 thanks i was also wondering about that

[@pdriaodra]

영어로 설명해주셔서 이해하기 조금 어려웠지만 엄청 유익하고 도움이 됩니다 감사합니다 !^^

[@seth85469]

this dudes a boss

[@pasindushavinda8066]

Really helped to understand the concept. ✌️✌️

[@samsonridge4526]

OOOOOOHHHHHHHHHH MY GOD.I JUST GOT SAVED.THANKS SIR

[@zeinabfarhat1920]

saved my life!!

[@AlaizaF]

Thankyou so much. T T The way you explain is just so smooth

[@duncanram]

A conical pendulum consists of a uniform straight bar (L) long and of mass (M), with a bob of mass (m) at its lower end. it rotates at (N rev/min) about a vertical axis through the upper end of the bar. How would you find the radius of rotation of mass (m)

[@duncanram]

how would you deal with a situation where the connecting arm/rod had a mass (kg)?

[@sers6561]

I love you soo much. So So So So SO So SO SO SOmuch

[@vasunith9682]

this question is the most basic question in India for anyone who is preparing for iit jee.......no offence and the teaching is really great and spectacular(CU)

[@rochaksinghthapakaji8319]

amzingly good

[@AlaizaF]

Thankyou so much!!!

[@alevelsdemystified3410]

Awesome video.

[@Cricketlover-sc8fm]

Thanks ☺️

[@praisemugodi4733]

I feel like im on top of a cloud.....☺☺thank you

[@sababatamanna2117]

Thank you!

[@subschallenge-nh4xp]

one year and you dont have any dislike you should be GOD

[@weenewman8123]

maybe because of your comment now it have 4 dislikes lol

[@calvinmuchemwa3880]

your comment triggered alot of shit

[@ryanlang2921]

You helped me so much!

[@dzunimthombeni9218]

well done,,I salute

[@spartenx8743]

Thank you💐💐💐💐💐

[@inthebackwiththerabbish]

I'm mesmerized 😂

[@alidarwish408]

Great video

[@laurachiriac1336]

GOOD TEACHERA AND TUTORIAL BUT HOW DO I DO FOR TWO MASSES SWINGING IN THE SAME HORIZONTAL CIRCLE.. I NEED HELP (AT DIFFRENT ANGLES)

[@chrislee5044]

You just saved my life.

[@graceb2404]

Nice example~

[@raselmahamudrobin4162]

Nice

[@EdwinFairchild]

ww@5:50 we do know that missing angle, 180-30-90 =60

[@mayankgoyal6495]

thanku sir

[@prashanttmg5432]

its ..awesome

[@yash1152]

Which software is used? And is a stylus & graphic tablet used too?

[@eolvra]

excellent

[@ainfatini2821]

Hye can u do vertical circle for angled centripedal force?

[@yash1152]

6:47 can theta be never equal to 90°?? Intro: I was stuck on a much more complex problem, and I thought of this case as it is the most simple case, but with angle theta = 90°. So, the next question was, what is balancing the mass here (when theta is 90)?? On a little bit searching, I found this: physics.stackexchange.com/a/277016 But this answer is voted -1 as of 2019.12.08 . So.... Also, just a quickie: this case is called a conical pendulum (for sake of a shorter & more precise search keyword 😃).

[@tunauzel]

If theta equals to 90° ,the y-coordinate of tension equals zero.Thus there won't be any forces that makes total force of x coordinate zero. So it is not possible.

[@bleuemoone8710]

How do you solve for the angle if you are given the velocity???

[@johnnywong5150]

@ 5:44, if we know two angles, you can determine the 3rd angle if it’s a right triangle 🥴

[@arthurmorgan4460]

Got an exam tomorrow and im only half way through what i should know. It's 6pm, looks like an all nighter. *nervous laugh

[@NightLapseStudios]

what if you dont know the angle, but you know L and the velocity and g? is it impossible? to know the angle

[@sgpaints9257]

On my practice exam they have this problem exactly, but they ask you to express Newton's second law in the radial and tangential directions. They end up with Fr = T - mgcos(theta) = m^2/r and Ft = -mgsin(theta) = mat I don't understand how the radial direction is not towards the center of the circle where the equation would be Fr = -Tsin(theta).

[@joesiu4972]

IM HERE FROM MY BOI AUSTIN

[@mirzabaig5583]

nice video

[@prod.hxrford3896]

but what do you call the vertical component of the string tension?

[@prankie727]

What happen if angle is 90 degree. In this scenario which force balance the weight (mg) of the body

[@jayjalloh3912]

Shouldn't T (y-axis) be sin30?

[@Alexander050101]

Do you know how to calculate the extension of the string if you knew the time period and radius too?

[@tunauzel]

If you know time period and radius you can calculate speed. And ıf you know speed you can calculate the x coordinate of tension. But if you want to find total tension force ,you also need to know the angle between it.

[@aldrichdias9086]

if I had to find the time can I use Vc=2πr/t to find it or is there another way

[@anc4002]

How would you find the length of the string...

[@mrchedda]

How to solve for the angle if given velocity?

[@bleuemoone8710]

how to do this?

[@lordpinochetuttp3819]

The method depends on what variables you have to work with. If you have the velocity, radius and mass, do the following: Calculate horizontal force by rearraging the velocity-centrifugal force equation. v^2/r = Fx/m , Fx = mv^2/r. Calculate the upward force by using classic F=ma. Fy=9.81m. Lastly, calculate the angle by using the tangent function. Divide the Fx by Fy and plug the result into the inverse tangent function. The answer is the angle which the rope makes with the vertical.

[@CompositeAcoustic]

What happen to the yellow m in the first equation?

[@bryanguzman6333]

what if I wanted to find the angle given the speed, mass, and length of string

[@tunauzel]

Firstly, you can find tension. Let us call them Ty and Tx. If you want to find the angle between them you can use Arctan(Tx/Ty) .

[@arunimachakraborty4596]

"Zeros are wonderful. They make calculation easier."😂😂😂

[@Ashleenaccarato]

He forgot the extra 'm' at 6:40. You get (m^2*g)/cos(30). And I got 101.8 N

[@josephsoo5318]

Get good

[@lasokl3718]

how do you find V if you dont know L or R?

[@deekshasingh8882]

how to solve for tension when angle is not given but mass length nd velocity is given

[@scotty15002]

deeksha singh You can find the X-component of the tension from the velocity and solve the angle measure from there.

[@bleuemoone8710]

Can you elaborate on this? I'm not quite sure how you'd go about doing that. I have the same setup as deeksha.

[@jaimed.campos2146]

why isnt there a normal force on the FB diagram?

[@radhab5408]

If the object is in contact with the surface then only we will have normal force acting perpendicular to the surface

[@andredubbs4854]

you just saved MY ASS thank you

[@danbeale6818]

My Professor got this wrong in class today

[@taykeith3795]

6:48 is probably the reason you clicked this video. The rest is waffle

[@taykeith3795]

I never knew this video was gonna include a waffle recipe. Not grateful

[@kingfly6858]

Bruh do u even breathe

[@jannatoitri6692]

That's also my question 😊😊

[@fearisallie]

Thank you, this really helped me!

[@chrisc1072]

Thank you for this

[@mirzabaig5583]

nice video