Work and Energy 02 | Energy | Kinetic Energy | Potential Energy | Class 9 | NCERT | Sprint

[@PW-Foundation]

📝Download Lecture Notes From PhysicsWallah App : bit.ly/2SHIPW6 🎯 Science group- t.me/joinchat/RYszj_1cAl8xEvnv 🎯 Social Science- t.me/joinchat/GCBE5bDgFdxrZeI8 🎯 Mathematics group- t.me/joinchat/GBbG4p5S_OVRV920 ----------------------------------------------------------------------------- 🗓️ Scheduled Syllabus For Sprint ( Class 9th ) released describing which topics will be taught for how many days. Available at PhysicsWallah App :bit.ly/2SHIPW6 •Duration:-1 month (Jan 2021 - Feb 2021) 🎉 Free Batch Exclusive on our KZbin Channel : Physics Wallah Foundation - 9 & 10 •Batch Details : 1) Best Faculties across India for different Subject/Topics. 2) Complete & Relevant Syllabus Coverage of Class 9th within 1 Month - Fastrack January 4,2021- February 15,2021 3) Monday - Saturday : Scheduled Classes everyday. •Physics : Tuesday, Saturday •Chemistry : Wednesday , Friday •Mathematics : Monday, Wednesday, Friday •Biology : Wednesday , Thursday , Saturday •S.ST : Tuesday, Thursday, Saturday, Sunday 4) Scheduled Syllabus released describing which topics will be taught for how many days. Available at PhysicsWallah App :bit.ly/2SHIPW6 ----------------------------------------------------------------------------- OUR SOCIAL MEDIA PROFILES : ⭐Instagram Handle : instagram.com/physicswallah/ ⭐Facebook Page: facebook.com/physicswallah ⭐Twitter Account : twitter.com/PhysicswallahAP?s=20 ⭐ PW App on Google Play Store : bit.ly/2SHIPW6 ❤️ Padhai Karte Rahe, All The Very Best 👍

[@abhirajpratap9141]

Hiii

[@mrpanda2498]

In concept Building question no.2 minus isliye laga hai kiyu ki wo body ko rok raha and displacement and force in opposite directions me hai.

[@ayushparkash152]

Because he want to ✋object it can't displace the object but object can't change its direction so it is negative

[@ayushparkash152]

Is it ✅ or not

[@videoworld7078]

Gajab

[@shreemiyaduvanshi1811]

26:19 workdone came negative because the force applied on the object to stop it was in the opposite direction to the displacement of the object. THANK YOU VERY MUCH SIR! Your explanations are great.

[@himanshusingh-B]

correct

[@raksha958]

Sahi h

[@abishugupata625]

yes

[@starlab5296]

Yes

[@alwinsjoy6961]

​@@abhigyanmishra9438 When breaks are applied to stop a moving vehicle, the force acts in the opposite direction of displacement, So we take the work done as Negative

[@sprihagaur]

26:29 ~ To stop the object, the force applied is in the opposite direction of object moving which creates a 180 degree angle, making the workdone negative.

[@Abhishekyadav-wk8ol]

You are right. Good

[@vanshyadav1646]

I am also right

[@indianeducationzone3176]

Same

[@NayakAyash-he5on]

Well bro

[@nirupamananda9234]

Correct🎉

[@PriyankaSharma-kz5xy]

26:25 jab bhi force aur displacement opposite direction mein hote hain , tab workdone negative ho jata hai

[@shabnam1071]

27:10 Workdone is 4mv square And per cent is 800 percent... Sir u teaches the best 👌....

[@sushiladevi2041]

Correct...

[@ojas.0012]

Niceeee

[@ansh.sharma3926]

Absolutely right👍

[@rinkaaazdssigarg3169]

(Final -initial /initial )×100

[@the_real_prabhat]

26:20 , Sir..for example, Displacement right me tha, usko rokne ke liye force left me lagaya.. Toh dono ke bich ka angle 180° bann gaya.. And formula = F × s × cos. And Cos180 = -1 So, Answer negative me aaya 👍👍

[@yashhjaiswall]

9:11 Sir, I was thinking about this method only but you are great and a legend in our term.

[@callipainting761]

I didn't know about this channel my sister told me about this channel and from that time I forgot all the other u tube channels 🤣😂😂

[@Gamer-fd1kv]

Same bro

[@imperfect7443]

Etna jhut or chut hazam nahi hota hai

[@rajnishagarwal1448]

Same pinch 😂😂

[@radhikagoyal8453]

Literally yes

[@pradiptakumarkar4488]

Same here

[@souravkumar9058]

26:33 Work done is negative because the force is applied to stop the body and it's opposite direction ❤️

[@mtsindiangamerz]

Yes 🙋

[@opp4ushorts_1]

You are right but we can say angle between force and displacement is 180°

[@ArnavSingh-go8pq]

The force acting to stop the object is friction force that is in opposite direction that' s why it is negative

[@aditi7346]

26:33 workdone is negative since the force is applied to stop the object that is the force applied would be on the opposite direction than that of the displacement .. Hence , the workdone would be negative..

[@poonamkitchens]

BTS ARMY!!!

[@aditi7346]

@@poonamkitchens Yep!💜😁

[@aditi7346]

@@poonamkitchens Hbu?

[@swaritrai4995]

You're absolutely correct

[@renurathore5489]

Are u an army ⟬⟭💜

[@byomthakur3374]

Challengers 1)-mv²/2 2) Becomes zero 3) Because ground is considered zero level and pot energy = mass * g * height from ground and when object is placed on ground h = 0 So, mgh = m * g * 0 = 0

[@Aryan725_]

U r write 👍👍

[@sportslovers1462]

Superb anwers dear

[@byomthakur3374]

@@sportslovers1462 THANKS BRO

[@Shivhari_calisthenics]

@@byomthakur3374 Q2 Brother if an object freely falling then it potential energy transferred to kinetic energy along height Then it's completely comes in rest (on ground) then it's totally mgh becomes zero converted to kinetic energy. So , the object when reached on ground then it all mgh becomes ke. So , it's have kinetic energy, Not zero

[@subhashrana8073]

2nd and 3rd answers are wrong kinetic energy is highest at ground

[@priyankamehrotra.4409]

Too good man...idk what to say....u r the only teacher with whom I can read physics with intrest

[@AjayKumar-jr7vl]

Yes you are right

[@vishubhai7495]

Yes u are right 💯

[@manishsinghmk9893]

Hlo

[@infinitygaming7331]

No ur wrong😎

[@abhajha9311]

26:31 The work done is negative because when we apply force to stop the ball it's make a 180 degree and we know 180 degree is a part of negetive workdone.

[@pratyhuhs]

Work done is never negative. It's always an absolute (positive) quantity.

[@rishighuriyani23]

Because we have stop the the body so we applied the force in the opposite direction the angle will be 180 so the answer will be in negative cos180 = -1

[@sobansingh7465]

Work done is negative because force is acting oposite side of displacement... You are best teacher of physics love from uttrakhand

[@sanjananegi1872]

I am also from uttrakhand

[@rajivnagar02haldwanirural11]

Me also ....aa Chu ham pahadhi ...😌

[@Officalvegeta749]

Go watch alakh sir`s videos

[@anonymous-sm6sh]

32:50 😂😂 26:23 Because the work is negative work and thetha is 180 degree and force is acting in opposite of displacement 28:00 sir answer is 800% Challenger question 1. -1/2 mv² 2. When object comes in contact with ground .energy conversion happens . Like sound energy , heat energy etc 3. No sir , If object is at rest on ground . Clearly it has KE,P.E(due to height) =0 . But sir the object can posses other forms of energy as well like P.E(due to configuration ) and also solar energy , wind energy , electric energy. Hence Energy =(not ) 0 .

[@pearl_yyy]

2nd wale me pucha hai uske K.E kya hogi

[@2027iisc]

@@pearl_yyy usme pucha hai ki uski kinetic energy ka kya ho jayega answer is ki uski kinetic energy sound heat and all me change ho jayegi

[@_lifestyleofshreya_]

king of physics @rakshaksir salute to the way of teaching and craking funny jokes in between make me smile everytime.... THANK YOU SIR

[@BR.ESPORT18]

Hii

[@sarthakgautam_]

50:17 yes sir you are right we apply force in upward direction we just decrease the amount of applied force in the upward direction.

[@amritayadav1035]

Hw ans is 1- an object moving with constant velocity if we aply the force opposite of it then it come to rest then work done is negative 2- it's kinetic energy convert into heat energy and sound energy and also potential energy because it shape change due to collapse to earth. Because of these it produce sounds. 3- no

[@manishsinghmk9893]

Good

[@rishi8997]

49:42 sir hum smuggling nahi karte 😉

[@AkashSingh-lj7ow]

26:30 because in this case angle formed force and displacement is 180°🙏🙏

[@nileshgarg4599]

Ohh bhai sahab OP 🔥🔥

[@AkashSingh-lj7ow]

@@nileshgarg4599 kya op bhai

[@Krizzjain-_-31]

1.If force and displacement are in opposite direction, workdone called negetive 2. Angel between force and displacement is 180° 3. It will increase the speed (RETARDATION) 26:28

[@arvindthakur2506]

Sir literally aap se physics padh ke bahut Maza aata hai aur har ek concepts ek hi baar Mai mind Mai set ho jaate hai. I'm you're great fan Sir ji.

[@visheshrattan699]

%age change in kinetic energy = final K.E -Initial K.E /Initial K.E ×100

[@Devang360]

No i thik u are confused btw 2 formula of delta kinetic energy and formula to convert energy in percent

[@lavanykandwal1817]

26:24 Work done is negative because the work is trying to stop the mass and to stop, we need to apply force in the opposite direction of the displacement which means angle between force and displacement is 180⁰ which hence means work done is negative .

[@lovelysrivastava3243]

1xactly

[@anshikaverma2680]

26:28 because we have to stop the particle and the angle between them is 180° and Cos 180° = -1

[@HeadPSKAZIM]

1.) 1/2* m/v² 2.) when object ready to fall it energy is "mgh" and as it fall it's potential energy convert into kinetic energy and increase in kinetic energy in increasing in it's velocity. When object touch the ground it's kinetic energy is in higher level and when object stops it's kinetic energy is become zero 3.) Yes ,an object on ground so it is not in motion so the kinetic energy is zero and object height from ground is zero so it's potential energy become zero and and sum of potential and kinetic energy is mechanical energy as both energy is zero mechanical is zero so every point of energy seen is zero

[@odeus...3857]

Sir Work done is negative because the Force applied and the displacement that took place were in opposite direction and formed an angle of 180° . Now the value of cos theta 180° is -1 and Work = Force x Disp. x cos theta That is why work done is negative and it also means that it is a retarding motion.

[@powerofpositivethoughts3188]

So nice lecture sir , love you sir , sir aap Jaan ho hamari , thank you so much sir , aap ki bahot help mil rahi hai , sir aap God gift ho sabke liye , sir all India apke sath hai , thank you sir from all India🙏

[@onepenonetab6663]

right bhai

[@abhimanyukumar4552]

Humko padi mai nhi lagta ke karu

[@CommerceKaur599]

40:03 😂 " Bccho karvayi to workdone se hi start hoti hai " 😂 Hats off to u sir ❤️

[@sanskarkumar464]

Can someone please explain to me how Is downward force the same as gravity? At 50:56 sir said that it will take the same amount of force to displace the object downwards as it took to displace the object upwards. I mean, if it took me to lift a 6 kg object with 10 newtons of force upwards, to bring it down, it should take less than 10 N of force.

[@YashKumar-zd9sj]

If you apply force less than (mg) there will a sudden displacement of the object downwards.... To avoid that we should take force equal to (mg) .. ...Correct me if you get a real solution for this...

[@prithvi__09]

@@YashKumar-zd9sj aukat mein

[@rupeshroy6276]

Love you sir from (bihar)India

[@rudrapratapsingh4104]

Pagal ladki padhne aye h ya shadi karne

[@rupeshroy6276]

@@rudrapratapsingh4104 "kala achhar bhains brabar" sab "love you" ka matlab wo nahi hota jo tum soch kar comment kiye ho.

[@CreepyGoogle]

26:31 Because angle between both force and displacement is 180° means -1

[@danceclassdc9824]

26:26 work down is negative because we are stopping train

[@mohitsingh9a542]

Sir your explanation is very perfect i understand this chapter very easily thank you so much sir

[@parakramdwivedi4035]

26:22 sir kyuki body ko rokna tha toh uska negative force lagegi

[@shreyashrivastava1055]

26:29 when force and energy are are in opposite directions....and the angle between them is 180°, then work done will be -ve

[@RishavPlayz2007]

cos theta becomes -1

[@manishsinghmk9893]

Good

[@sachinmehta8564]

Sir you are amazing teacher of physics there is no sir like you.

[@Anwesha01]

36:45 Sir! Potential energy ko classification ka kya need h?

[@aryanmittal1325]

Sir please explain Relationship between kinetic energy and momentum.

[@atharvapratap4462]

Increase in kinetic energy would increase the momentum of a body and decrease in kinetic energy would decrease the momentum of body

[@krishnakaushal8834]

Q1 - K.E Q2. Its K.E ----》P.E Q3. If the object h=0 from the ground and it is at rest so the. P.E + K.E. = Zero. And sir i have a doubt if we are in space so then also the object should have the P.E . And sir class is awesome 👌

[@LeviAckerman-xk4xg]

Yes I also have that question

[@mrinalsahu5713]

@@LeviAckerman-xk4xg IDK much ( i m also a 9th grade student ) Just sharing my POV ( do research by ur own , my POV can be wrong also , i m not responsible if u get less scores ). PE needs a relative level ground to calculate . AND in gravitation it says every mass attracts to each other . So in space there will be at least something to relate ( for example moon/satellite is relative to earth ) by gravity . So, we can find the height for displacement . Here is the definition of PE :- the quantity determining the energy of mass in a gravitational field or of charge in an electric field ( copied from google ). OR simply a stored energy which defines how much energy it will use to perform a certain displacement … since displacement is a vector quantity it needs a two relative points . The object will have PE accordingly .

[@mrinalsahu5713]

@Technoblade rest in peace 9 mahine pehle likha tha .... ab toh mujhe bhi samajh nhi aa rhaa🤦‍♂🤦‍♂😅😅...basically relativity ka khel hai....agar koi cheez space me hai toh uska mass..aur baki falna calculate karne ke liye ek relative matter chahiye... so potential energy uske hisaab se lagega.....deep space me shayad hi minute figures honge pr wo zero nhi hoga...kyonki space actually me bhara hua hai..........mai galat bhi ho osaqta hoon teacher /proff se consult kar lijiyega

[@surendrayadav9535]

Force and displacement are opposite direction so workdone is negative 26:34

[@akpro4666]

Hats off to you sir ❤️ Thank you soo much for putting so much effects to teach us ❤️ 😊

[@aliabbas4122]

Sir really l have seen so many teachers...but no one is like you.... really you are the best teacher...

[@PriyankaSharma-kz5xy]

28:11 q3 delta KE = 4mv² % change = 800%

[@pranavmaheshwari3152]

I am studying this chapter again bcoz of class 11th and sir's lecture is super great op

[@iayt2284]

41:45 Sir,In case if we are applying same force as earth then it will termed as balanced force and balanced force can't produce acceleration, then how is it possible to lift that object...🤔😊

[@fakihatariq9149]

Balance force does not produce acceleration but it can produce uniform velocity😂😂

[@snehatallapu]

You need to know first law of motion for answer

[@Anwesha01]

26:14 Sir! Esliye aaya kyu ki body ka direction aur force ka direction opposite hai aur voh 180° ka angle form kr rha!

[@arya3692]

Challenger questions : 1.) Workdone =-1/2mv^2. 2.) K.E=0 3.) It has no energy because it is on ground and it is taken as a reference point and also it is not moving...

[@infinitegamer1747]

Sir you are teching us like a legend............ Next level Explanation❤

[@kindnessgamer2388]

🖖🖐🖐🖐🖐

[@prateekkumar539]

26:38 because force applied to stop the car is in opposite direction of the car's displacement

[@vaibhavgupta8814]

Very nice exaplaination sir This is very helpful video 🙏

[@Krish0012]

workdone came negative because the force applied on the object to stop it was in the opposite direction to the displacement of the object. THANK YOU VERY MUCH SIR! Your explanations are great.

[@tutugamer436]

Thanku

[@SayantanEditx]

Workdone will be negative as it will decrease the speed(redarded) and angle between F and S is 180° 26:29

[@Sahil-ot8uo]

Sir apke padhane ki wagha se mere physics me full marks aaye haim😊

[@akshaysinghrajpurohit1163]

Bhagvaan jo bhi is comment ko like kre uske maa, baap ki umer bandha do

[@aryanhoque6944]

Tujh mein akal ki kami hain naa neech log

[@GyanPrakashPatel100]

Bhai Aisa mat Kiya kato yar tumhari bhi maa hai

[@anshumanpathak500]

Bhai bhagvan comment padhne aayenge

[@yashyadav3211]

Bakchodi Mt pale

[@Anwesha01]

26:26 Sir! Jahan se stop krenge uss place ka angle aur object ka position ka angle 180° form krega as dono ke direction opposite h, that's why!

[@RajeshSingh-hy8kp]

1- in order to bring the object to rest the work done must be equal to K.E of moving object =1\2 MV square 3- yes

[@factoboy1295]

The only thing I want to say is - "Best video ever 🔥🔥🔥🔥" salute you sir

[@Jayant_Thaware]

26:34 sir as there is 180 degree between applied force and the displacement means the F and S both are in opposite directions so workdone is negative

[@mahreenfatima6883]

Tomorrow is my exam I don't know how my paper of physics gone but when I find your channel now I understood all topics of chapter work power Energy thank you sir ❤️❤️❤️

[@rajkumarwagh9293]

😮

[@humanbeing...8230]

Thank you sir ... Your way of teaching is absolutely amazing. ...you have cleared all my doubts and confusion of this topic ... Once again thank you so much sir ...💜💜💜💜

[@knowingmyself6372]

Tae opp😉😉💜happy new year army💜🤗

[@bonobonoya4983]

Aay...namjoon will be proud of us 😉

[@knowingmyself6372]

@@bonobonoya4983 Yes he will😂😂🕶

[@renurathore5489]

Are u an army

[@sivi9948]

Look here also i found army ... 💜💜💜😂😂😂😂💜💜💜

[@MUJTABAHASSANCHOWDHURY]

42:07 sir,how will there be any movement in the object because we are applying mg in upward direction and gravity is pulling it donward direction So both are balanced so if we apply equal force so net force is zero so the object shouldnt move....😐

[@LeviAckerman-xk4xg]

29:45, can I write 8×1/2mv^2 as 4mv^2 ?

[@jasvindersingh6011]

Yes

[@bhanuvlogs4593]

Who is watching this in 2024 😅

[@AdityaSharma18383]

Me

[@_Play_With_Avd_]

I am watching in 2112😅

[@sampurnabiswas4102]

Me

[@arunPrasad-kv9zt]

Me

[@AbhishekOjha-r8t]

Me😊

[@ourtargetf1283]

01:03:12 question 3. Yes the energy will be zero because of we know that kE=1/2mv^2 -1/2mu^2 and body is in rest. And there is no displacement.

[@Pragati_23]

Sir negative isliye aaega kyuki apn force lga rhe displacement ke against or angle bhi hoga 180degree isliye wd negative hoga...

[@leyla_tv16393]

So sad that I can’t understand the language but he had clearly explanation, love you teacher 👨‍🏫

[@noobgamer4103]

Why?

[@aryanhoque6944]

Are u deaf ?

[@MUJTABAHASSANCHOWDHURY]

26:25 Sir, workdone is negative because the force applied to the body was in opposite direction of displacement. As cos theta= 180° therefore,so the value of cos180°=-1 So upon multiplying the values we get -1125J

[@kshatriyaParth]

26:23 Answer, because of retardation force. Force is one direction and displacement in opposite direction

[@DrOtaku112]

Yes

[@lsing6553]

Love you sir ❤️

[@SanjayKumar-it4qf]

Gay hay kya

[@lsing6553]

@@SanjayKumar-it4qf mtlb

[@football-lover.7]

26:29 Because we need to stop a body so final velocity = 0. U = 1125 And when we subtract v-u so we get negative workdone

[@mohammadamanatalikhan]

sir thank you soo much for this wonderful lecture

[@baddestgod513]

26:23 because the opp. Force acts on it and it moves forward, so, the angle between them is 180° and we know that cos180° = -1 so the fscos theta will be -fs which represents the negative workdone 😊😊

[@HamzaKhan-tf9or]

Right ✔

[@vanshkumarreedy75]

Sir u said that we always take gravity as negative if we take g as neagtive then sir weight can never be postivite and the question u discuss in the 55:30 sec this will also in valid . So i think we dont have to take g always negative but only sometimes like in free fall concept😕😕

[@vanshkumarreedy75]

Sir if u have clarity about this then plzz discuss with us😊😊becoz u the best physics teacher of 9th class😊

[@prt4691]

Dekho bhai g ko negative lene ka meaning hai ki humne yeh mana hoga ki uper wali Direction +ve hai Kyuki g hamehsa niche act kar raha hai Aur Acceleration is a VECTOR quantity iska matlab hai ki uski Direction represent kar raha hai Isiliye sir ne waise kiya Hope samaj gaye hoge 👍

[@vanshkumarreedy75]

@@prt4691 bro calculation invalid kr jati ha🤐

[@vanshkumarreedy75]

Bhai sir ne free fall me minus ko b calculation me add kia tha that's why m asking . Thanks for convence but i don't get clarity so plz coment to sir for dicussion on this topic😊

[@Aanya1xbook]

Your explanation is amazing 🙏👍

[@aryavlogshybelabels5106]

hii

[@prochef9218]

26:19 Cos ø = 180° opposite direction 180° =-1 That's why

[@harshvardhanpate913]

Question Number 2 work done is negative because the object displace forward and force is in opposite directions .So we know that when force and displacement are in opposite direction then there is negative work done and create angle of 180 degree.

[@suryasishmukherjee268]

26:22 It came negative because we are applying force in the opposite direction which slows the moving object to v=0 so the work done is negative.

[@Sakshi_sharma....9]

Sir thankuu Very good explanation sir Video dekhte hue interesting bhi lgti h 🥰🥰

[@palgauravpal_________418]

Thanks Rakshak sir ❤😊

[@Gamingvideos-l6c]

Please support me ❤❤😅

[@kshetreyapadekar9113]

i solved the olympiad lvl question aur kis kis ne kiya?? 🕉🕉🕉🕉

[@deepakkumarmishra5776]

Yes

[@himanshukumar7455]

😭😭😭😭 bahut bahut dhanayabad hame youtube ke jariye padhane ke liye.

[@shiwanikhokhar1993]

Great lecture 👍🏻👍🏻👍🏻👍🏻 Very interesting.

[@Musicworld-fg1gz]

26:27 Theta 180 degree and cos180 = -1

[@rajvinderkour2213]

Sir you made my life so easy and make the physics enjoyable ❤you are amazing 👏 👏 ❤ I really like your teaching style you are mindbolwing sir 🎉

[@jagyannarayanpati7069]

because angle between f and s is 180 degree

[@uditanshukumar120]

Negative because we applying force in the opposite direction of the displacement

[@gauravhere1832]

👍👍

[@isha8854]

Am i only one here who fell in love with physics because of, awesome teaching style of rakshat sir🥰..

[@Sigmaroyal1]

😮but here is also a physics lover.❤

[@GhostRider-mj5uy]

❤❤❤😂 i am also😃❤❤❤

[@aakarshsrivastava1579]

26:25 the workdone is negative because the force is acting in a direction which is opposite to the direction of motion (displacement)and making an angle of 180 degree. This type of workdone is negative workdone. BTW you are an awesome teacher of Physics.😀😀

[@user-iz5uc5vq1c]

Sir kya padha reh ho aap ... seriously I can't describe you in comment section... seriously..I wish that you teach us ... chemistry or bio too....sir ..I am so satisfied to see your lacture... thanks sir ...

[@iffatkhan4771]

ANS:- When an object falls freely, its potential energy gets converted into kinetic energy. When the object hits the ground, its kinetic energy gets converted into heat energy and sound energy. THIS EXPLANATION IS FROM MY TEACHER AND ANSWER IS FROM ME:-) Explanation:- When an object falls freely towards the ground, its potential energy decreases, and kinetic energy increases; as the object touches the ground, all its potential energy becomes kinetic energy. As the object hits the hard ground, all its kinetic energy becomes heat energy and sound energy. It can also deform the ground depending upon the ground’s nature and the amount of kinetic energy possessed by the object. Kinetic energy is a property of a moving object or particle and depends not only on its motion but also on its mass. Potential energy is stored energy that depends upon the relative position of various parts of a system

[@vedanshsahu-rj1xk]

Sometimes light and vibrations too

[@anitakirtak3599]

Sir you are amazing teacher of physics

[@proveenkumargupta4661]

Sir mujhe sirf aapki class me maza aata h ...

[@harshichaudhary1021]

27:55= change in kinetic energy = 4mv² Percentage = 400%

[@halalguy99]

I got the correct answer of this question i.e 800% But After watching your comment I got confused

[@ourtargetf1283]

01:03:12 question 2 . When the object reaching the ground the kinetic energy convert into chemical energy.

[@ayushraj3575]

Sir , if a body is at rest ,it has zero kinetic energy.a train which is in motion it will have kinetic energy,but with reference to another train which is moving parallel and with equal constant velocity ,both of them will be at rest with reference to each other,in this case will kE will be zero?

[@pankhurisworld8341]

Very good beta

[@ayushraj3575]

@@pankhurisworld8341 mind your language

[@nirbhaysingh4232]

There is negative work done because velocity has decreased

[@gamosuraj7974]

26:22 work done = -1125 (negative is because , when we subtract large number from small number, answer is always in negative and the small number is 0 ) sir Mane maths lagai btw - is liye aaya hai q ki hum log ball ko stop kar rha hai

[@amishchaudhary9765]

sir olympiad level question 1st bar mai sahi aya without help thanks sir :)