Newton's 4th law says that every book continue to be in rest until and unless internal or external exam appears and speed of page turning is directly proportional to the syllabus to be covered and tension in the mind remains constant.
Introduction - 00:00-02:03 Workdone - 02:04-16:47 Calculation of Work: Positive Work - 16:47-23:54 Calculation of Work: Negative work - 23:55-27:04 Calculation of Work: Zero Work - 27:05 to 34:42 Why do we pay coolie/porter ? - 38:28 to 43:32 ENERGY - 53:24 to 57:02 Kinetic Energy - 57:03 to 59:55 Finding experssion of Kinetic energy - 59:56 to 01:05:40 Potential Energy - 01:19:51 to 01:26:46 Finding experssion of Potential energy (position) - 01:26:47 to 01:29:00 Potential Energy - 01:35:11 to 01:35:36 Understanding Potential Energy (Configuration) - 01:35:37 to 01:37:49 Law of conservation of energy - 01:37:50 to 01:41:10 Examples of conservation of energy - 01:41:11 to 01:47:06 Proof of conservation of mechanical energy - 01:47:07 to 01:57:03 Power - 01:57:04 to 01:59:19 Relation between Kinetic Energy and Momentum - 02:11:29 to 02:14:35 Relation Between Power, force and velocity - 02:14:36 to 02:16:03
Dekho! Yaha pr question mein bola gya h ki 'ek block h ya tum maanlo ek box hai usmein jetni bhi forces lag rhi hai voh sb bata na h, toh figure ke according block mein 3 Forces lg rhi h 1.Gravity(g) 2.Applied force (jo box ko move krne keliye lgaya gya h) 3. Frictional force Tmhe sbka workdone batana h, toh phele separately nikalo example- applied force- w=fs w=20x10 w=200 waise hi bakyion ka nikalo aur sabko add krdo kyuki Net workdone pucha h (net ka mtlb whole ya pura)
@@sheshkumarSingh-sf8xt Dekho! Shesh waha pr workdone pucha h aur maine workdone ka formula use kiya h which is W=fs and question mein given h ki F=20N S=10m Thus, W=fs W=20x10 W=200J
@@VishnuSharma-dr2yi Listen I'm not sure about this..as far as I know, mass is not calculated.. Well if you have any doubt then I would ask this to my teacher to clear some doubts🙏🏻
Thank you so much I think that so and my answer is also coming this but sir calculated mass in every question that's why I have doubt in this and I also ask my teacher about this
Timestamps Introduction - 00:00-02:03 Workdone - 02:04-16:47 Calculation of Work: Positive Work - 16:47-23:54 Calculation of Work: Negative work - 23:55-27:04 Calculation of Work: Zero Work - 27:05 to 34:42 Why do we pay coolie/porter ? - 38:28 to 43:32 ENERGY - 53:24 to 57:02 Kinetic Energy - 57:03 to 59:55 Finding experssion of Kinetic energy - 59:56 to 01:05:40 Potential Energy - 01:19:51 to 01:26:46 Finding experssion of Potential energy (position) - 01:26:47 to 01:29:00 Potential Energy - 01:35:11 to 01:35:36 Understanding Potential Energy (Configuration) - 01:35:37 to 01:37:49 Law of conservation of energy - 01:37:50 to 01:41:10 Examples of conservation of energy - 01:41:11 to 01:47:06 Proof of conservation of mechanical energy - 01:47:07 to 01:57:03 Power - 01:57:04 to 01:59:19 Relation between Kinetic Energy and Momentum - 02:11:29 to 02:14:35 Relation Between Power, force and velocity - 02:14:36 to 02:16:03
H/W W1= Fs costheta =20×10×cos0°(As F and s are acting in same direction so angle b/w them is 0°) =20×10×1(Value of cos 0° is 1) =200J(Ans.) W2= fs cos theta =5×10×cos180°(As f and s are acting in opp. direction and angle b/w them is 180°) =5×10× -1 = -50J(Ans.) W3= f¹(let force be f¹)×s× costheta =mg ×10×cos 90°(As weight of body is acting perpendicular to the displacement of body) =5×9.8×10×0(Value of cos90° is 0) =0J Work done by all the forces acting on the block is W1=200J; W2= -50J; W3=0J Net workdone is {200+(-50)+0} J =150 J
time stamps Introduction - 00:00-02:03 Workdone - 02:04-16:47 Calculation of Work: Positive Work - 16:47-23:54 Calculation of Work: Negative work - 23:55-27:04 Calculation of Work: Zero Work - 27:05 to 34:42 Why do we pay coolie/porter ? - 38:28 to 43:32 ENERGY - 53:24 to 57:02 Kinetic Energy - 57:03 to 59:55 Finding experssion of Kinetic energy - 59:56 to 01:05:40 Potential Energy - 01:19:51 to 01:26:46 Finding experssion of Potential energy (position) - 01:26:47 to 01:29:00 Potential Energy - 01:35:11 to 01:35:36 Understanding Potential Energy (Configuration) - 01:35:37 to 01:37:49 Law of conservation of energy - 01:37:50 to 01:41:10 Examples of conservation of energy - 01:41:11 to 01:47:06 Proof of conservation of mechanical energy - 01:47:07 to 01:57:03 Power - 01:57:04 to 01:59:19 Relation between Kinetic Energy and Momentum - 02:11:29 to 02:14:35 Relation Between Power, force and velocity - 02:14:36 to 02:16:03
52:05 work done by applied force Work done = Fs cos ∅ = Fs cos 0⁰ = 20×10×1 Work done by applied force = 200 J Work done by gravity Work done = Fs cos ∅ (mg)× s cos 90⁰ ( 5×10) × 10 × 0 Work done by gravity = 0 J Work done by friction Work done = Fs cos∅ Fs cos 180⁰ 5× 10× -1 Hence, work done by friction = - 50 J Net workdone= 200+(-50)+0 200-50= 150 Joules Answer
@@VishnuSharma-dr2yi workdone=FxSxcos theta so, workdone by friction=5x10xcos180o =50x-1 =-50J so here we can see that mass is not included in the calculation and so mass is not required in questions of mass.It may be given to trick the students.
37:45 THIS MINUS SIGN IS BECAUSE OF THE VALUE OF COS 180DEGREE THAT IS -1 THE MINUS SIGN INDICATES THE NAGATIVE WD AND THE DIRECTION OF DISP IS OPPOSITE FROM THE DIRECTION OF FORCE
@@lizarahman__ because the force of friction is 5N and is applied in the opposite direction so the angle(cos theta) will be 180° which is equal to -1 So by multiplying 5 x 10 x -1 You get -50J
at 1:35:08 the ans should be 300J as the obj is lowered down to the height of 5m instead of bringing it down 5m. Now s will be equal to 10 and the ans will be 60X10 = 600J and now on subtracting W2 from W1 (900-600) the ans will be 300J
37:46 The minus sign indicates that the speed of the object is slowing down due to negative workdone. In other words we can say that ,the object is experiencing retardation. 51:40 Workdone by applied force = 200J Workdone by friction force = -50J Workdone by weight force = 0 J Net Work done = 150J 2:11:18 Total Cost = 48*3 = Rs.144
Because of upward direction and force being downwards so 180° tells -1.🎉 It tells that the work is done in the opposute direction of force. 38:04 Speed is slowed down
48:05 sir , you have mentioned g is 10 , i agree you can take g as 10 but students will think that g is always 10. Actually g is 9.8 but for easy calculations sometimes we can take 10😊
37:57 It is because here the force is acting in opposite direction to displacement so here we will use formula :- *W= F•sCOSTHETA* = F•sCOS 180° = F•s×-1 😊😅❤
1:33:01 sir the object is brought down to the height of 5m so from 15 m it will come down to 5 m so the equation formed will be w=60x10xcos 180 w=600x-1 w=-600
🎉🎉 I was searching for all the videos uploaded by u sir and u r an excellent teacher seriously!!! I hv watched all your videos even of all classes that u teach because I like ur way of teaching physics which gives me interest in physics and I m liking this subject studying from u now sir🎉🎉
That negative sing had occurred because the value of cos180° = -1 If we multiply it Fs cos theta Then, 20×10×7× -1 = -1400 Jule The - sign denotes that both forces are working on opposite direction In simple words it defines retardation 37:45 Am I right? 👇🏻
In my school the teacher is even worst than yours , She finished a typical chapter i.e, Gravitation within 4days without the pursuit of understanding of her students
51:53 HOMEWORK ANSWERS. 1) W1 = 200J ( by force applied) 2) W2 = -50J (by force of friction) 3) W3 = 0J( by force of gravity) Net work done = 200+(-50)+0= 150J Thank you sir ☺️☺️
@@VishnuSharma-dr2yi yup , we did but only in finding the downward force , which is mg(mass×gravity) . We did not use mass in finding the other forces .
37:54 Here the work done came as -1400 Joules indicate that the force and displacement are in the opposite actors. And it is termed as negative workdone. Here also the cos 180° termed or known as the value of -1 as per the shown tablular form.
51:27 the positive workdone will be 200J The negative workdone will be -50 The zero workdone will be 0 The net work done will be 200+(-50)=>200-50=150J
the sign "-" came because the angle creates between the force and displacement is 180 degrees. Since cos180 is equal to -1,then answer will come in negative form.
37:55 BECAUSE WHEN THE ANGLE IS 180 DEGREES THEN COS THETA = --1 AND 10X20X7X-1 AND AS + x + = + and - x - = - therefore 10x20=200 and 7 x -1=-7 therefore 200x-7=-1400 swaha
H/w : Net force: big - small = 20 N - 5N = 15N W1= fs cos thita = 15N × 10m× cos0( because force and dislacement acting on same direction) = 15N× 10m×1(cos0=1) = 150j W2 = fs cos thita = mg×s× cos90( because the force is acting in downward direction and displacement is forward. so it will make 90 ° and cos90 =0) = 5kg ×10 ×10 m× 0 = 500 ×0 = 0j The total work done = 150j +0j = 150 j.
Sir there is a sign of minus because the force is acting downwards and the displacement is being upwards so the angle between them is 180 degree and the value of Cos180 is -1.
@@WanzeenWhen we say Zillion, we are generally using it to emphasize a vast quantity without providing a numerical value or simply it means many many thanks or something........
51:29 sir work done by the applied force is 200 J ; work done by frictional force is -50 J and work done by force of gravity is 0 J And the net work done is 150 J
37:50 whenever there is a negative sign in case of workdone , it shows that the angle between force and displacement is 180' and the value of cos 180' si -1 The impact of it is that it would responsible for the reduction in the speed of the object as the force is exerted on the object in opposite direction.
Thank you sir, This zero to hero batch is really helping me a lot but can u upload such videos a bit fast so that we can start revision because kvs PT 3 exams are starting on 23 January.
37:51 minus sign is there because force is in the opposite direction of the displacement so we've taken cos theta as 180 which is equal to -1 so the answer has a minus sign.
