It's perfectly valid. That's because the friction always works in the opposite direction of the motion. The fact that Sal said that the friction was pointing to the left sort of gives away that the boulder is going to the right, though.
.Balance forces are two forces acting in opposite directions on an object, and equal in size. Anytime there is abalanced force on an object, the object stays still or continues moving continues to move at the same speed and in the same direction.
Hi Sal, and thanks a million for such a wonderful library of videos. However, could you possibly number/otherwise categorize the videos on your channel? It's sometimes hard to know which playlist your recently uploaded videos belong to. Greetings from Finland!
Another question: For the bottom right picture, since you are adding 1N to the regular 2N of friction, would you not add 2N again but this time to the 4N of friction because the little guy is pushing also?
The force of gravity (g) is drawn from center of mass. However, the normal force (n) should be drawn from where the force is beeing applied (between the rock and ground).
what if you have a square that has all different numbers for example top is 10N bottom is 5N right is 3N and left is 12N. Do you solve up and down first and left and right second?? Would the answer be 5n with a direction of up and 9N with a direction going left?
Because the rock is moving to the right, so the force of friction acts to the opposite direction. i.e. if both guys were applying equal forces, there would not be any friction force. ;)
Question: since the rock has a mass, why isn’t there a Normal force acting at the opposite direction of the guy pushing? I believe this is two surfaces, no? So if there’s friction, that would mean the normal force would be whatever Force the guy is pushing in the opposite direction PLUS the force of friction, also in the opposite direction. Does that make sense? So, for example, in the second scenario, the normal force on the x axis would be -4N. Or should we also count the guy’s force of friction in the positive x direction? In other words, I’m mixed up…. :)
Also, last example at the end of the video. You have to people pushing against eachother, 4N to the left, 3N to the right, so the net is 1N to the left, but what about the 2N of friction to the left? Is this just no longer a factor when people become a factor? Should the 2N of friction not also be accounted for and the net be 3N to the left?
Correct me if I'm wrong, but wouldn't the second guy pushing the rock also be impeded by friction? I know that even with that, it will be unbalanced, but I just wanted to raise a point.
please make advance Lagrangian and Hamiltonian mechanics vids , and and quantum mechanics, quantum field theory, QED, strings omfg i am so excited finally some physics omfg *dies of heart attack*
Yeah, that makes sense but how does it add up with the person pushing against the movement? Is that person's force-vector already partially the 2N Force of friction? In that case, the person only pushes with 1N, right?
How do you know what the force of the static friction acting on an object will be in order to figure out exactly how much force needs to be applied to move the object?
When you are sitting down, you have inertia. Friction only works when you are in motion, it slows you down. So when you have inertia, until a force acts upon you, you cannot be slowed down if you are already stationary.
It not that he would have trouble learning it himself (which, in all likelihood, he would), it's the absurd amount of time and effort that would have to be put in to making the relevant videos. It would consume all of his time, and probably only a handful of people would end up watching them anyway.
I don't know if such a scenario is possible. if you're apply 1N force on it and the force of friction is twice as much: 1N-2N= -1N which means the object will accelerate opposite to the direction of your force. But the force of friction opposes motion, it does not create it( then again I'm not an expert either)
Video needed to start at minute 5 when you had all of the diagrams drawn already. You repeating yourself a million times just to fill the silence while you draw your diagrams is highly distracting and a waist of time. Draw the diagrams CLEANLY PRIOR and then record the video while getting straight to the point.
It's perfectly valid. That's because the friction always works in the opposite direction of the motion. The fact that Sal said that the friction was pointing to the left sort of gives away that the boulder is going to the right, though.
.Balance forces are two forces acting in opposite directions on an object, and equal in size. Anytime there is abalanced force on an object, the object stays still or continues moving continues to move at the same speed and in the same direction.
Sal, you have no idea how many futures you lighten up every time you put together an explanation!!
"The rock is green...the rock is brown...the rock is resting on the ground"
Dwayne johnson approved this video
Lalxiam Khuptong Lol
haha
Haha lol
The rock is brown 4:01
LOLOLOLOL😂
wooow very info
yes very info
2021 and still the best vid I have watched today
super very clear explanation
Hi Sal, and thanks a million for such a wonderful library of videos. However, could you possibly number/otherwise categorize the videos on your channel? It's sometimes hard to know which playlist your recently uploaded videos belong to.
Greetings from Finland!
Yes, that's what I understood. The person on the right pushes with 1N and there's an additional 2N due to friction, adding up to 3N.
I lv the way you teach
Finally, some Physics videos. You haven't made them in ages.
Another question: For the bottom right picture, since you are adding 1N to the regular 2N of friction, would you not add 2N again but this time to the 4N of friction because the little guy is pushing also?
MercifulAreWe the little guy is pushing for 1N and that's already accounted for when Sal added the 1N to 2N force of friction
i understood it you made it really simple
Thank you very much for this videos....they are AWESOME!!!
Thanks so much, this helped my understand unbalanced forces just before my Physics exam :D
You helped out so much! Thank you!
Excellent video! Thanks for sharing.
The force of gravity (g) is drawn from center of mass. However, the normal force (n) should be drawn from where the force is beeing applied (between the rock and ground).
I'm watching this for a test :)
Same
But shouldn't the force of friction act against the little orange man too, I mean the force towards the right should be 5 N ????
@Sebastian Carbajal Gomez not gonna fall for it
BUT STIIL the purple guy wins the rock pushing competition
No, because the rock was not gonna move anyway, he was pushing at 1N and the rock's friction was 2N. The little guy just makes it harder for him.
شكرا
I get it now. It makes sense in hindsight. Thanks.
12 yrs ago wow, how are you now??
Question:
in last scenario, why isn't the force of friction affecting both guys the same way?
Because frictional force acts opposite to direction of motion
I was thinking the same thing too
hi sal really loved your explanation helped so much
what if you have a square that has all different numbers for example top is 10N bottom is 5N right is 3N and left is 12N. Do you solve up and down first and left and right second?? Would the answer be 5n with a direction of up and 9N with a direction going left?
I love you mahn.. I freakin love you!
legend thx man
Because the rock is moving to the right, so the force of friction acts to the opposite direction. i.e. if both guys were applying equal forces, there would not be any friction force. ;)
I get it now....thanks...🇧🇩🇧🇩🇧🇩🇧🇩🇧🇩🇧🇩🇧🇩🇧🇩🇧🇩🇧🇩🇧🇩🇧🇩🇧🇩🇧🇩🇧🇩🇧🇩🇧🇩🇧🇩
6:38
Dis is kewl
Question: since the rock has a mass, why isn’t there a Normal force acting at the opposite direction of the guy pushing? I believe this is two surfaces, no? So if there’s friction, that would mean the normal force would be whatever Force the guy is pushing in the opposite direction PLUS the force of friction, also in the opposite direction. Does that make sense? So, for example, in the second scenario, the normal force on the x axis would be -4N. Or should we also count the guy’s force of friction in the positive x direction? In other words, I’m mixed up…. :)
Also, last example at the end of the video. You have to people pushing against eachother, 4N to the left, 3N to the right, so the net is 1N to the left, but what about the 2N of friction to the left? Is this just no longer a factor when people become a factor? Should the 2N of friction not also be accounted for and the net be 3N to the left?
3N is the sum of two forces, one from person i.e 1N and 2N of air friction
this video helped me so much!
Correct me if I'm wrong, but wouldn't the second guy pushing the rock also be impeded by friction? I know that even with that, it will be unbalanced, but I just wanted to raise a point.
Thank you it’s so awesome and I understand in easy way 😍😍😍
please make advance Lagrangian and Hamiltonian mechanics vids , and and quantum mechanics, quantum field theory, QED, strings omfg i am so excited finally some physics omfg *dies of heart attack*
Hii
From where are you
thank you
Yeah, that makes sense but how does it add up with the person pushing against the movement? Is that person's force-vector already partially the 2N Force of friction? In that case, the person only pushes with 1N, right?
Needs more Lubricon VI.
since the overall acceleration is to the right friction will only oppose this motion
How do you know what the force of the static friction acting on an object will be in order to figure out exactly how much force needs to be applied to move the object?
khan knows everything!!! X)
So friction is only created when we try to move, or move something? It is not just there?
When you are sitting down, you have inertia. Friction only works when you are in motion, it slows you down. So when you have inertia, until a force acts upon you, you cannot be slowed down if you are already stationary.
Ok, then it makes sense. Didn't seem quite clear to me from how Sal presented it.
2.09 why should the force of friction be 2N
"QFT and strings"
Sorry, but that's a little far-fetched. Intro QM and general relativity is do-able though.
the rock is green.... the rock is brown... haa the rock is resting on the ground HAHAHAHHAHA best part
So wich one of these is the unbalanced
Cute
If two unequal forces are applied on an object in opposite directions, then.
Sir can you help me with this 😫
@Unicorn Unicorn Thanks a lot 😊
😊
Can this be an free body diagram?
no
You sound like TheDevKing...
It not that he would have trouble learning it himself (which, in all likelihood, he would), it's the absurd amount of time and effort that would have to be put in to making the relevant videos. It would consume all of his time, and probably only a handful of people would end up watching them anyway.
Look at him now
That's some weird friction, only going against the one guy but not against the other one. (Scenario 5)
At 4:07 I expect Sal saying that's not Brown..
this is the easiest video and simple video khan academy has every made.
hi evry one!!!!!!!!!!!
whats the definition of net force???
Net force is the vector sum of forces acting on a particle or body. For example, the pictures that are being drawn on the video above.
Please use dark colour
Unbalanced forces answer "Washington, DC!!!!!! LoL,Lol That really is the answer. LOL
kindly use brighter colored pens
if i have pushed a rock with 1n and it has friction of 2n what is going to be the case?
I don't know if such a scenario is possible. if you're apply 1N force on it and the force of friction is twice as much:
1N-2N= -1N
which means the object will accelerate opposite to the direction of your force. But the force of friction opposes motion, it does not create it( then again I'm not an expert either)
+Maha Agro thank you anyway 😊
You would not move at all. Maga Agro, that doesn't make sense because thene everything would be accelerating in some direction if noting is hapenning,
What your class english laja ka
In the fifth scenario shouldn't there be friction counter-acting the push to the left?
no
Ok me desespero este video un poqui
VERDAD
wtf is natural force? the rock moves the earth; only its motion is basically imperceivable.
😴😴😴😴😴
I'd like to think the guy on the right in the 5th example gets squashed over by the rock xD Btw who's watching in December 2019?
not me
Rti
Who's here in 2024
Bully pa tu ok
boring
marce1812 it is meant for educational purposes not fun
First speak correct ok
omfg , thanks for showing all us 3 year olds how to play add/subtract with numbers 1-5. jesus..
..
Flick off hater
I have the app on my phone
Why am I stressing myself
Video needed to start at minute 5 when you had all of the diagrams drawn already. You repeating yourself a million times just to fill the silence while you draw your diagrams is highly distracting and a waist of time.
Draw the diagrams CLEANLY PRIOR and then record the video while getting straight to the point.
Ap ki voice isn't nice