They incorrectly think of the two masses, pulling down on the rope as opposed to realizing that the rope is simply transmitting the force from one mass to the other. That’s why you always have to draw the free body diagram for a particular object and really pay attention to the forces acting just on that object.
This guy is literally saving me in College Physics w/ Calc right now!! Sir, you're literally explaining better than any other video I've seen out there. Guys, look through his channel!! It's a game changer I promise!
18:46 i though tension will be zero as from both sides 9.8 on the same rope but if we image the tension going upwards they will cancel each other out, can you clear my this doubt please
Start by looking at just one mass. Since the mass is at rest (not accelerating) the net force on it must be zero from Newton's 2nd Law. Therefore the magnitude of the tension must be equal to the weight of the mass (mg). Think of the tension in the rope as the way the two masses communicate their presence with each other. So each mass is pulling up on the other mass with its weight.
The blocks will move together, so they will have the same acceleration. Another way to think about it is to picture the two blocks together as one big mass of 30 kg. So the acceleration of both blocks together is equal to the applied force divided by the combined mass. This is what my solution shows.
Think of the tension as the way each mass exerts a force on the other. So these have to be equal (think Newton's 3rd law). What will be different for each mass is the net force
![Newton's 2nd Law of Motion in Physics Explained - [1-5-6]](http://i.ytimg.com/vi/5T_O6Zt5Xt4/mqdefault.jpg)
Heroes don't wear capes, they explain physics in a simple and quick way, big thanks from Belgium! ;)
Wow, thanks!
19:43 how do people even get b? The net force is 0, so mg=T, same mass and mass=1. I'm curious how some got that wrong.
They incorrectly think of the two masses, pulling down on the rope as opposed to realizing that the rope is simply transmitting the force from one mass to the other. That’s why you always have to draw the free body diagram for a particular object and really pay attention to the forces acting just on that object.
This guy is literally saving me in College Physics w/ Calc right now!! Sir, you're literally explaining better than any other video I've seen out there. Guys, look through his channel!! It's a game changer I promise!
Thanks!
I have a quiz tomorrow hopefully this will help me
Good luck!
@@smithjomiddlesexedu I did very well ! 19/20 Thank you professor
Your welcome!
You are great professor, thank you
At first quesiton, why we didn't use Fn for calculating acceleration.(NOT FNETX)
cause at the y direction the acceleration is zero there is no acceleration there, that is why we did not use the Fn because Fn is in y direction
Thank you so much for this easy to understand video, now i'm confident that I'll ace my physics quiz
Glad to help!
😭😭what if you're required to calculate the pull force itself?
You would have to be given the acceleration. Then you could calculate the pull force from that and the mass using Newton's 2nd Law.
So helpful!! You are amazing!
Glad it was helpful!
thanks man, i have a pilot assesment with an airline on 25th needed this to brush up
Your welcome!
AAAAA THIS HELPED ME SO MUCH IN MY FINALS
Great!
this video was super helpful, than you so much professor.
You're very welcome!
18:46 i though tension will be zero as from both sides 9.8 on the same rope but if we image the tension going upwards they will cancel each other out, can you clear my this doubt please
Start by looking at just one mass. Since the mass is at rest (not accelerating) the net force on it must be zero from Newton's 2nd Law. Therefore the magnitude of the tension must be equal to the weight of the mass (mg). Think of the tension in the rope as the way the two masses communicate their presence with each other. So each mass is pulling up on the other mass with its weight.
in the 2nd example how does F12 = F21 while both have different masses
From Newton’s Third Law. The force that object one exerts on object two must be equal in magnitude to the force that object two exerts on object one
Thank you sir
super helpful video thank you
you're welcome!
tnks professor
18:42
Did you have a question?
Am not sure about acceleration on the second example
The blocks will move together, so they will have the same acceleration. Another way to think about it is to picture the two blocks together as one big mass of 30 kg. So the acceleration of both blocks together is equal to the applied force divided by the combined mass. This is what my solution shows.
23:56 why the tensions are equal the masses are different>???
Think of the tension as the way each mass exerts a force on the other. So these have to be equal (think Newton's 3rd law). What will be different for each mass is the net force