What is Relativistic mass? & DERIVATION (variation of mass with velocity)

[@FortheLoveofPhysics]

Relativistic Kinetic Energy ► kzbin.info/www/bejne/iqiuhHqMgMt8jtk

[@DApple-sq1om]

At 20 minutes I strongly suspect M=m1+m2 can not be correct, hence this derivation fails. m1 depends on u1,m2 depends on u2, and M depends on v.

[@anasfarid2492]

Watching your lectures from past two years. No one is making such a high quality content on YT at least in subcontinent. Thanks for being available, For making us love Physics. From 🇵🇰

[@mrhasan7867]

kzbin.info/www/bejne/h6PCeXqbepekrNk

[@physics-theworkingofeveryt6086]

HAI SIR I AM PRAJIT REDDY... I HAVE BEEN SEEING YOUR VIDEOS FROM MANY MONTHS.....YOU WILL NOT BELEIVE BUT I AM 11 YEARS OLD AND I UNDERSTOOD EVERY TOPIC I SAW..... YOU ARE THE BEST PHYSICS TEACHER IN INDIA.....SALUTE TO YOU ..👍👍

[@saswatpati9281]

Hello Sir. Want to thank you for communicating with such a degree of clarity and interest. Honestly amazing. Much love from Australia

[@bishalbasak9081]

Anybody want to know where the idea of "relativistic mass" was created? Go and read feynman lectures vol 2 page 28-3 to 28-4

[@kidslearningbymadhankarthi6114]

Amazing teaching skills... Very clear derivation!!!!

[@stochasticxalid9853]

Dear Sir, i just wanted to say thank you for your passion, it is contaminating. Your explanations are amazingly clear, your handwriting is impeccable and your way of conveying the message is astonishing. A new subscriber here. My respect❤

[@अहमस्मियोद्धा]

I'm a big fan of ur teaching sir ... Please keep educating us ... Respect 🙏

[@ujjwalyadav8780]

Hlo sir I'm watching ur videos since 1 yr they are awsm🔥🔥

[@FaizKhan-xp4mp]

Very informative video sir and as usual your teaching method makes it very easier to digest... ☺️

[@aadithyn3338]

Under-rated you saved me sir ❤️. Top class explanation, my tutors taught me this like something really complicated...but after seeing this i understood everything. ❤

[@starryfolks]

Keep making such videos please. Very good explanation with professionalism and insight so that a common person can understand. I wish to be knowledgeable in physics without having a degree in it as demand and pay is low and I don't want to dedicate my entire time on it. Such videos are wonderful.

[@niranjanca3534]

wonderful explanation sir thank you

[@oduroojuni3241]

i found right place for relativity at last!

[@NumbToons]

At 39:55 we dont "define" a new velocity 'v'. Actually 'v' is the velocity of the S' frame, and if we want u2 to be zero, then u' for m2 should be equal and opposite to velocity of S' frame. Hence, the 'special case' we are considering is when particles in S' frame are moving with velocities 'v' and '-v'

[@gargipatil6261]

you are amazing. Made it so freaking easy!

[@bishwajitbhattacharjee-xm6xp]

Thank you for love for physics videos. It makes sense why it is special relativity, what love is all about.

[@dirtman4796]

I asked this question to one of your students and he recommended me your video.

[@SS-mn7le]

THANKU VERY MUCH SIR🙏

[@amslowvoltage]

I like your videos!!!! I watch and I lost myself in my past student life where I used to study this relatively with a lot of curiosity!!!!! Thanks

[@vinayreddy4266]

Sir make a video series of astrophysics of Bsc final year sir plz plz....bcz ur teaching method is very easy to understand by students 🙇

[@Tzadokite]

here is an interesting derivation using the time dilation expression of STR: we have t(v)=t(0)*(1-v^2/c^2)^1/2. we write this as frequency 'f', which is defined as frequency = 1/time. hence we have f(v)=f(0)/(1-v^2/c^2)^1/2. for constant 'v' we have df=df(0)/(1-v^2/c^2)^1/2. we have dE=dP/dt *dx or dE*dt=dP*dx=k. this gives us dE*dt=k and dP*dx=k. from these one can obtain the heisenberg's uncertainty expressions. however, if we take dE*dt=k and write it as dE=k/dt we get dE=k*df, because df=1/dt as frequency = 1/time and for frequency = df we have df = 1/dt where dt = time. from dE=k*df we obtain E=kf+C where C is the integration constant. if when f=0 we have E=0 then C=0. hence, E=kf. of course from we can shown that k=h and obtain the general expression E=hf of which the planck expression for energy quanta or photon is a special case. hence E=kf(0)/(1-v^2/c^2)^1/2. from E=kf we get E(0)=kf(0). hence, E=E(0)/(1-v^2/c^2)^1/2. again for kinetic energy E(KE) we have E(KE)=E(v)-E(0) or {E(0)/(1-v^2/c^2)^1/2 } - E(0) = E(KE). for v

[@The_Green_Man_OAP]

40:14 Correction: u2=0 => m2=m1√(1-u1²/c²) & m2=m2(rest) u1=v & u2=0 => m1=m2(rest)/√(1-v²/c²) ...(1) ~~~~~~~~ Also, if u1=0 => m1(rest)=m2√(1-u2²/c²). => m1(rest)=m2(rest) , from above. ~~~~~~~~ => (1) can also be written as: m1=m1(rest)/√(1-v²/c²) However, this is just for the specific situation where: m1(rest)=m2(rest). ~~~~~~~~~~~~~ So, are you saying the mass of one object is dependant on the rest mass of the other..? 😕 Also, are we conflating 'mass in a rest frame' with 'all masses at rest' ..❔😕

[@ugursoydan8187]

very good video. thanks for your lobor

[@NRUSINGHAPRASADMAHAPATRA]

Thank you so much Sir 😊🙏🙏

[@antarippal3344]

this is very complicated calculations is this importent to come in semester exam ??

[@kanyarwandacyprien]

Nice

[@aravindrpillai]

Awesome

[@SyedTanvirAhmadRoomy]

Dear Debojyoti, Relativistic Mass is a Popular Wrong Concept (!). This truth is clear to those who work in Advanced Field Theories. Please make a video on that.

[@The_Green_Man_OAP]

Gamma (which can be written: γ=c/√(c²-v²) ) is not coming from the mass, it's coming from the time dilation. That's how it was derived in the first place. Classical: Momentum = (mass)*(displacement)/(time) p=mv, with v=dx/dt, dx=lab displacement & t=lab clock time. Maybe, for Relativity it should be... v=dx/(dt/γ)=γ(dx/dt) ...??? So, we must question what dt/γ=dt' is... If t=lab time, then perhaps t' is object time. Then p=mv, but with fixed m & clock is with an object that is moving relative to the lab frame and therefore with "dx" measurements of displacement in the lab frame. However, need some sort of "mass deficit"; _Why not_ consider a _mass flux_ which gives you a _mass differential_ between two points along a trajectory (i.e. two points in "spacetime coordinates")? So, to formalize this so far, I am saying: Relativity: Momentum = (mass)*(lab displacement)/∆(object time) p=mv, with v=dx/dt' & t'=object clock time such that dt'=lab time / gamma=dt/γ. Using gamma definition: γ=c/√(c²-v²), We have: dt/γ=dt/c/√(c²-v²)=(dt/c)√(c²-v²) So: v=dx/dt'={c/√(c²-v²)}.(dx/dt) c/√(c²-v²) can be interpreted like a trig ratio, with c as the hypotenuse, so it seems to be either like 1/sin or 1/cos. However, as v→c it approachs ∞, so to counter this, maybe adjust "dx" also... _length contraction_ ?🤔

[@rangaiahkaravadi5340]

Even though the transfer of electrical energy takes place from one end to the other in a wire at a very high speed ( at speed of light ) the actual speed of electrons in the wire will be very very low ( drift speed of electrons ). Now for an observer moving in a rest frame of a +ve charge his speed relative to electrons will also be very low. Hence at these low speeds, how can we apply the relativity principle for getting length contraction between the electrons? And also, how can we say that Magnetism arises from relativity? Please clarify, thanks.

[@arghajitlodh5672]

Sir, please make a video for oblique collision

[@argujjar835]

I was waiting for this video

[@mrhasan7867]

kzbin.info/www/bejne/h6PCeXqbepekrNk

[@o.om.m5632]

What happens to m as v approaches c or c from the left in the equation m=mo/sqr(1_v^2/c^2)

[@abhilashassariparambilraja2534]

What is the minimum accelerating rate to become infinite mass according to special relativity theory 🤔?

[@AnwarKhan-ni9dz]

Thank ur sir ❤

[@bishwajitbhattacharjee-xm6xp]

Hi it is those two factors Elastic scattering and law of physics of momentum conservation makes the speed barrier on mass. The constancy of velocity of light in 4D space time hyperbolic geometry and zero intervals space -time stop the physics invarent . Because as the speed approaches to constancy. How one should justify this geometry of mass flatness to a observer! Universe is full of free style mass .Is it a optical collapse , as an example " mirrage" . Is it ?

[@aayushde8257]

at 15:40 there is a mistake: "When the 2 bodies are in contact they are at rest with 0 velocity."

[@nkosanadetermine7404]

Hey don't forget we are solving what frame S is observing , hence S ' frame is moving with velocity V

[@talktivevlog4004]

Here we assume that the collision will be elastic so it the reason that it's velocity will not 0 (w.r.t S' frame)

[@derphysik8243]

Please make videos on GTR

[@HighEnergyScientist]

Bro explain about schrodinger equations

[@rakibulhasan8840]

21:19 23:48 25:36 29:06 30:21 31:58 34:56

[@anasahmad3859]

thanks for using green board . a great fan of you from pakistan

[@hareecionelson5875]

It's a good day when you can do the difference of squares

[@legendAnkit-we6dc]

You are a professor at Hanshraj College under DU. am I right?

[@Artoverme]

Tq sir 🙏🙏🙏🙏🙏

[@sumankumar_phy0987]

Is mass and energy are equivalent or they are just self-contained? Lets say I'm in space and at rest, of course I've the mass but do I have energy means can I say I have energy or I would have to say I have just mass and I have no energy but I which have mass may converted to energy. You are a professor so you would answer correctly.

[@bikajikonthoujam7228]

Tq. Sir

[@DApple-sq1om]

At 20 minutes I strongly suspect M=m1+m2 can not be correct, hence this derivation fails. m1 depends on u1,m2 depends on u2, and M depends on v.

[@pquantum69]

দাদা তুমি offline পড়াও কোথাও?

[@sylvainbrosseau6239]

I love your teaching skills. Just want to stress that nothing is at rest. In the universe, everthing moves. So what do we call 'rest' is a relativistic term. It would be Rest relative to you. Same thing, speed is a relative term. An object really has all speed and no speed at all. So what's the kinetic energy when the object has all speed and no speed at all? Mixing the energy that would propagate if you transform the object totaly in energy and Kinetic energy which really is a unidirectional force vector is silly to start with aside from using it for experiments with LHC. It is worth mentioning because the saying goes it is impossible to go faster than speed of ligth because of the "relativistic mass". If it is not possible to go faster than 'c', someone has yet to explain it to me without using the concept of relativistic mass.

[@frankdimeglio8216]

I have mathematically unified physics. Here's the CLEAR proof. The ultimate unification and understanding of physics/physical experience combines, BALANCES, AND INCLUDES opposites, AS E=MC2 is CLEARLY manifest as F=ma ON BALANCE; AS ELECTROMAGNETISM/energy is gravity. Here's the proof. This also explains why objects (including WHAT IS THE FALLING MAN) fall at the SAME RATE (neglecting air resistance, of course), AS E=MC2 IS CLEARLY F=MA ON BALANCE; AS ELECTROMAGNETISM/energy is gravity. TIME dilation ULTIMATELY proves (ON BALANCE) that E=MC2 IS clearly and necessarily F=ma ON BALANCE, AS ELECTROMAGNETISM/energy is gravity. Gravity is ELECTROMAGNETISM/energy ON BALANCE. ON THE CLEAR, EXTENSIVE, SENSIBLE, BALANCED, THEORETICAL, AND UNIVERSAL PROOF THAT ELECTROMAGNETISM/energy is gravity, AS E=MC2 IS clearly PROVEN TO BE F=MA ON BALANCE: Balanced inertia/INERTIAL RESISTANCE is fundamental, as ELECTROMAGNETISM/energy is gravity. The stars AND PLANETS are POINTS in the night sky. Energy has/involves GRAVITY, AND ENERGY has/involves inertia/INERTIAL RESISTANCE; AS gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites; AS ELECTROMAGNETISM/energy is gravity; AS E=MC2 is CLEARLY proven to be F=ma ON BALANCE. This NECESSARILY represents, INVOLVES, AND DESCRIBES what is possible/potential AND actual IN BALANCE. Indeed, A PHOTON may be placed at the center of what is THE SUN (as A POINT, of course); AS the reduction of SPACE is offset by (or BALANCED with) the speed of light (c); AS ELECTROMAGNETISM/energy is gravity ON BALANCE; AS E=MC2 is CLEARLY F=ma IN BALANCE !!! Gravity is ELECTROMAGNETISM/energy ON BALANCE, AS E=MC2 is CLEARLY proven to be F=ma IN BALANCE. TIME dilation ULTIMATELY proves (ON BALANCE) that ELECTROMAGNETISM/energy is gravity, AS E=MC2 is CLEARLY F=ma ON BALANCE. Gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE, AS ELECTROMAGNETISM/energy is gravity; AS E=MC2 is CLEARLY F=ma ON BALANCE; AS the stars AND PLANETS are POINTS in the night sky. Accordingly, ON BALANCE, the rotation of WHAT IS THE MOON matches it's revolution. TIME is NECESSARILY possible/potential AND actual IN BALANCE, AS ELECTROMAGNETISM/energy is gravity; AS E=MC2 is CLEARLY F=ma ON BALANCE. The stars AND PLANETS are POINTS in the night sky. Accordingly, ON BALANCE, it makes perfect sense that THE PLANETS (including WHAT IS THE EARTH) will move away very, very, very slightly in relation to what is THE SUN !!! ELECTROMAGNETISM/energy is gravity, AS E=MC2 is CLEARLY F=ma ON BALANCE. Inertia/INERTIAL RESISTANCE is proportional to (or BALANCED with/as) GRAVITATIONAL force/ENERGY, as this balances gravity AND inertia; AS E=MC2 is CLEARLY F=ma ON BALANCE; AS ELECTROMAGNETISM/energy is gravity. GREAT. I have explained the cosmological redshift AND the supergiant stars. Stellar clustering ALSO proves ON BALANCE that ELECTROMAGNETISM/energy is gravity, AS E=MC2 is CLEARLY F=ma IN BALANCE !!! By Frank DiMeglio THE FULL, BALANCED, EXTENSIVE, AND REAL MEANING (AND DERIVATION) OF E=MC2, AS ELECTROMAGNETISM/energy is gravity: TIME is NECESSARILY possible/potential AND actual IN BALANCE, AS ELECTROMAGNETISM/energy is gravity; as E=MC2 is CLEARLY and necessarily F=ma ON BALANCE. E=MC2 is CLEARLY proven to be the linked AND BALANCED opposite of F=ma, as gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites; as ELECTROMAGNETISM/energy is gravity; AS GRAVITY/ACCELERATION INVOLVES BALANCED inertia/INERTIAL RESISTANCE; as E=MC2 is CLEARLY and necessarily F=ma ON BALANCE !!! Carefully consider what is THE SUN, what is THE EARTH/ground, AND the fact that the stars AND PLANETS are POINTS in the night sky !!! TIME dilation ULTIMATELY proves (ON BALANCE) that E=MC2 is CLEARLY and necessarily F=ma IN BALANCE, as ELECTROMAGNETISM/energy is gravity. Gravity is ELECTROMAGNETISM/energy !!! Carefully consider the speed of light (c) ON BALANCE. The stars AND PLANETS are POINTS in the night sky ! Therefore, THE PLANETS (INCLUDING WHAT IS THE EARTH) move away very, very, very slightly in relation to what is THE SUN ON BALANCE !!! Great. Inertia/INERTIAL RESISTANCE is proportional to (or BALANCED with/as) GRAVITATIONAL force/ENERGY, as this balances gravity AND inertia; AS E=MC2 is CLEARLY and necessarily F=ma ON BALANCE; AS ELECTROMAGNETISM/energy is gravity. Gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE, AS E=MC2 is CLEARLY and necessarily proven to be F=ma ON BALANCE; as ELECTROMAGNETISM/energy is gravity. This is definitively proven by THE FACT that the rotation of WHAT IS THE MOON matches it's revolution. Gravity is ELECTROMAGNETISM/energy ON BALANCE, as E=MC2 is CLEARLY and necessarily proven to be F=ma ON BALANCE. Get a good look at what is the blue sky, as THE EARTH is ALSO BLUE. Now, look at what is the ORANGE SUN; and think lava. Consider what is the fully illuminated and setting MOON comparatively !!! The stars AND PLANETS are POINTS in the night sky. E=MC2 is CLEARLY AND NECESSARILY proven to be F=ma ON BALANCE, as ELECTROMAGNETISM/energy is gravity. This NECESSARILY represents, INVOLVES, AND DESCRIBES what is possible/potential AND actual IN BALANCE !!! Gravity is ELECTROMAGNETISM/energy. Carefully consider what is THE MAN who IS standing on what is THE EARTH/ground. Touch AND feeling BLEND, as E=MC2 is CLEARLY and necessarily F=ma; as ELECTROMAGNETISM/energy is gravity. Carefully consider what is THE EYE ON BALANCE !! GREAT. It all CLEARLY makes perfect sense, as BALANCE and completeness go hand in hand. “Mass”/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent with/as what is BALANCED electromagnetic/GRAVITATIONAL force/ENERGY, as E=MC2 is CLEARLY and necessarily proven to constitute F=ma ON BALANCE; as ELECTROMAGNETISM/energy is gravity. Gravity is ELECTROMAGNETISM/energy. BALANCED inertia/INERTIAL RESISTANCE is fundamental. Energy has/involves GRAVITY, AND ENERGY has/involves inertia/INERTIAL RESISTANCE. It is mathematically proven. So, this also explains the term c4 (from Einstein's field equations) along WITH what is the fourth dimension; as E=MC2 is CLEARLY and necessarily proven to be F=ma ON BALANCE; as ELECTROMAGNETISM/energy is gravity. TIME dilation ULTIMATELY proves (ON BALANCE) that E=MC2 is CLEARLY and necessarily proven to be F=ma ON BALANCE, as ELECTROMAGNETISM/energy is gravity. (Gravity is ELECTROMAGNETISM/energy.) The stars AND PLANETS are POINTS in the night sky. Consider what is the speed of light (c) ON BALANCE. Consider what is THE EARTH/ground. Consider what is THE SUN on balance. E=MC2 is CLEARLY and necessarily proven to be F=ma ON BALANCE, AS ELECTROMAGNETISM/energy is gravity !!! By Frank DiMeglio

[@FortheLoveofPhysics]

PDF notes are available on Telegram t.me/FortheLoveofPhysicsYT

[@DApple-sq1om]

At 20 minutes I strongly suspect M=m1+m2 can not be correct, hence this derivation fails. m1 depends on u1,m2 depends on u2, and M depends on v.

[@banshkumar3498]

🤷

[@dirtman4796]

Nuclear weapons shows the real potential of mass to energy conservation

[@fg1099]

Merci !

[@motif123456]

Many problems would begin to appear as sson as you introduce relativistic mass. Dr Don Lincoln of fermilab said this is an outdated idea and should not be encouraged to invest time in understanding. With moving particles ,relativistic mass would be more as they pass by earth.From earth frame those particles would now begin to become heavier.The gravitational law of Newton would then have relativistic mass in the numerator leading to huge problems. Thus the gravitational pull between earth and those flying particles would begin to approach infinity.

[@FortheLoveofPhysics]

I think you skipped my introduction

[@akshatpandey9373]

@@FortheLoveofPhysics The introduction is fine. It is just that there certain sentences that you spoke, for example "high energy is associated with an increase in mass" will only result in misconceptions. It should be stressed that 'relativistic mass' is just a convention and does NOT physically correspond to 'increase in mass'. It is a valid concern because introductory SR courses are prone to leaving people with misconceptions, hence the "paradoxes". Just a constructive suggestion. No offence meant.

[@akshatpandey9373]

@@FortheLoveofPhysics Dr. Sean Carroll puts it well here. kzbin.info/www/bejne/pJDcqZJ4p8mFfJo

[@anitalayal9171]

I can win a lot of money by betting on this topic 😁,, because this topic is too hard to understand and explain to others

[@RahulYadav-uy3yn]

Thank you so much sir