Thank you sir. So clear and easy but looks so hard in class. I would have dropped out of college if there weren't kind smart people like you uploading knowledge for free for world to learn
Years back when I was teaching undergraduate physics one the first few meetings in the class are actually to have some coaching the are how to take notes in class, then how to study and solve physics problems sort of build some confidence, outlook, and attitude to the difficult subject matter. Many high school graduates come out of the school dropping everything they learned or had classes on and we have to assume its ground zero again. Educational research in the Philippines shows that Filipino students are graphical thinkers so graphing and plotting and visualization is really an important content in-class delivery of not so popular classroom classes among freshmen.
For consistency we could rewrite for the second segment x_sub2 to have x_sub1 in and v_sub1 while following your 3rd segment notation x_sub3 that is written to be with x_sub2 and v_sub2 components in the equation
Your explanations are so very detailed and understandable. Thank You so much for this, I really appreciate it. Concerning the acceleration in finding v subnot for the second segment = final v for first segment, you put acceleration as zero whereas it is 0.5m/s in the first segment. Please why is this so?
Sir, im in 9th grade and didnt understand anything explainined in the video. We are being taught the same thing in class and i dont understand anything. Please help.
It is difficult to respond to your request since you stated that you don't understand "anything", so that we don't have a basis to start from. It is better to ask specific questions about a specific singular concept or equation.
Excellent kinematics video. I have one question though. Why is it when Kinematics is taught, there are no vector arrows drawn over the variables in the 3 equations? Is this because in 1D motion there is only a + and - direction? Thank you!
Ive read the comments... and I am wondering why for X of 2 (240 seconds) was not squared ? when it is for X1 and X2 ?? I have rewinded but cannot understand ??
Sir please clear my doubt. To get distance traveled we calculate the area under Velocity Time curve, which we usually do considering curve above X axis. But we could have compute the area under that curve with respect to Y axis. But why don't we do so? Please reply.
If we have a negative velocity, the velocity curve will be below the horizontal axis and there will be negative area representing distance traveled in the opposite direction.
The problem is divided into 3 parts. 1) The acceleration part 2) the constant velocity part 3) The deceleration part. In the second part, the initial distance for the second part is the distance covered during the first part which is 900 m.
Every motion problem uses the equations of kinematics. (Or are you asking when to use the graphical method and when just to use the equations?) If so, it is a personal preference. You can use both methods for every problem.
There are a number of ways to do this, but this may be the simplest: the distance an object falls is proportional to t^2 Thus if you want half the distance, when is t^2 = 1/2? When t = sqrt(2)/2 = 0.707 Thus a falling object spends 70.7% of the time to travel the first half and 29.3% of the time to travel the second half. Total time = 1/0.293 = 3.41 sec.
+Kemi Omodele x2 represents the distance traveled by the train at constant speed. Therefore there is no acceleration and thus the third term goes to zero (a = 0)
sir i have a question . from top of tower of height 20m, a boy drops a stone, after one second he throws another stone vertically downward so that both hit the ground together. The initial velocity of the second stone is?
You first figure out how long it takes the first stone to drop to the ground. (2.02 sec). Then you use that information to find the initial velocity of the second stone: Y = Yo + V0y t + (1/2) g t^2
Do you have like videos which go into the harder aspects of this topic because I'm kind of looking for that before my test. The simple parts I get, it's the non- constant acceleration that troubles me
Hi Michael, I wanted to ask you why we have sec, sec^2, sec^3 etc.. same with many other physics quantities where something is squared or cubed what does it mean ? Thanks
If a variable is squared mathematically the order of that variable is raised to 2 also an exponent of zero on a variable is to mean it raised to 1. A second-order variable say in a function if you plot them will result to a curve and not a line. Thus the component 1/2at^2 will result in a curve as our dear teacher has shown.
i have a doubt in my head. in the second segment, to find x2 , a=0 so why time is included?? If a=0 , then the whole 1/2 at^2 should be 0 right ? Anyone clear this up.
That is a good observation. The acceleration is constant over the entire period the train is accelerating, except at the very "end" points of the acceleration. We ignore those for the sake of simplicity as is done in all of lower division physics. If we don't these problems would become much harder as you will see in upper division physics or graduate level physics. Thus in this context it is fine to use that equation. Remain inquisitive, that is great.
Thank you sir. So clear and easy but looks so hard in class. I would have dropped out of college if there weren't kind smart people like you uploading knowledge for free for world to learn
Thanks for all your work. It's greatly appreciated.
best physic video I have ever seen! Thank you Dr!
Thank you sir, this is really helping me through physics 6A!
Years back when I was teaching undergraduate physics one the first few meetings in the class are actually to have some coaching the are how to take notes in class, then how to study and solve physics problems sort of build some confidence, outlook, and attitude to the difficult subject matter. Many high school graduates come out of the school dropping everything they learned or had classes on and we have to assume its ground zero again. Educational research in the Philippines shows that Filipino students are graphical thinkers so graphing and plotting and visualization is really an important content in-class delivery of not so popular classroom classes among freshmen.
Thanh you so much! In this state of quarantine i have terrible virtual lessons and you are my only help. From ARGENTINA 🇦🇷 I appreciate your work!
Hi Lua, Hang it there, we'll get through this. Welcome to the channel!
You are a life saver
Glad you found our videos! 🙂
Thank you sir your are the best
Thank you. Glad you think so.
For consistency we could rewrite for the second segment x_sub2 to have x_sub1 in and v_sub1 while following your 3rd segment notation x_sub3 that is written to be with x_sub2 and v_sub2 components in the equation
I love the Bow Tie!
Thank you for the video
Your explanations are so very detailed and understandable. Thank You so much for this, I really appreciate it.
Concerning the acceleration in finding v subnot for the second segment = final v for first segment, you put acceleration as zero whereas it is 0.5m/s in the first segment. Please why is this so?
The train is only accelerating in the first section, holding the same speed in the second section, and decelerating in the third section.
ı am so grateful sir , thank you for all the videos:D
Sir, im in 9th grade and didnt understand anything explainined in the video. We are being taught the same thing in class and i dont understand anything. Please help.
It is difficult to respond to your request since you stated that you don't understand "anything", so that we don't have a basis to start from. It is better to ask specific questions about a specific singular concept or equation.
thank you very much sir really appreciate your work it's so helpful 💚
Thank you very much, professor!
Thank you for making these videos!! They're the best! :)
Excellent kinematics video. I have one question though. Why is it when Kinematics is taught, there are no vector arrows drawn over the variables in the 3 equations? Is this because in 1D motion there is only a + and - direction? Thank you!
It can be done both ways, as long as one keeps track of the directions.
Ive read the comments... and I am wondering why for X of 2 (240 seconds) was not squared ? when it is for X1 and X2 ?? I have rewinded but cannot understand ??
During the time period 2, there is no acceleration. Therefore distance traveled (x2) is simply = v t
The Amount of Subscribers You Deserve is The Same as Your Current Amount , Just Replace "Thousand" With "Million" .
Thank you. We appreciate the value you place on our videos. Much appreciated.
Excuse me SIr, But why is the velocity 30m/s in the final segment of the graph?
That is the velocity at the beginning of the last segment, before it slows down to 0 m/sec
Marvelous work thank you very much.
thanks for the efforts!
Clear and very useful
Sir please clear my doubt. To get distance traveled we calculate the area under Velocity Time curve, which we usually do considering curve above X axis. But we could have compute the area under that curve with respect to Y axis. But why don't we do so? Please reply.
If we have a negative velocity, the velocity curve will be below the horizontal axis and there will be negative area representing distance traveled in the opposite direction.
why is the initial X 900m instead of 300m? @7:07
The problem is divided into 3 parts. 1) The acceleration part 2) the constant velocity part 3) The deceleration part. In the second part, the initial distance for the second part is the distance covered during the first part which is 900 m.
hello sir i have a question, how do you when to use which kinematic equation?
They can always be used as long as the acceleration is constant. (They don't work if the acceleration is not constant).
Michel van Biezen ok and how do we know which problems to use the kinematic equations on?
Every motion problem uses the equations of kinematics. (Or are you asking when to use the graphical method and when just to use the equations?) If so, it is a personal preference. You can use both methods for every problem.
You see what is missing from your equation. If for ex you have time missing you use the time independent equation
I noticed we couldnt use the formula: s = ((v+v0)/2)t - why is that?
That equation is not one of the three equations of kinematics. If there is acceleration then s = (1/2) a t^2
So X2 = X1 + V1 t + 0.5 at squared
X2 = X1 + v t X3 = X2 + (1/2) at^2 (for the last part)
@7.07,,why can't we find the velocity by finding the slope from the graph,instead of using 1st equation?
You can. There are often multiple ways to find the same solution.
there are many ways to find velocity
At X3 8:47, before subway moved 900(x1) + 8100 (x2).However, you just added 8100 why ? x0=9000 at there Isn't it ?
+CloneComCody
The 8100 m for x2 already includes the 900 m from x1.
x1, x2, and x3 are all relative to the origin.
a body dropped from a tower travels half of the total distance in the last second of its motion. The total time of fall will be?
There are a number of ways to do this, but this may be the simplest: the distance an object falls is proportional to t^2 Thus if you want half the distance, when is t^2 = 1/2? When t = sqrt(2)/2 = 0.707 Thus a falling object spends 70.7% of the time to travel the first half and 29.3% of the time to travel the second half. Total time = 1/0.293 = 3.41 sec.
hi , why wasn't the time in x2 squared ?
+Kemi Omodele
x2 represents the distance traveled by the train at constant speed. Therefore there is no acceleration and thus the third term goes to zero (a = 0)
Thank you so much.
You're welcome!
sir i have a question .
from top of tower of height 20m, a boy drops a stone, after one second he throws another stone vertically downward so that both hit the ground together. The initial velocity of the second stone is?
You first figure out how long it takes the first stone to drop to the ground. (2.02 sec). Then you use that information to find the initial velocity of the second stone: Y = Yo + V0y t + (1/2) g t^2
thank u sir
can i ask u more questions
When I have time (I am very busy).
Michel van Biezen check my calculations, but wouldn't the initial velocity then be 14.6 m/sec?
Thank you
Do you have like videos which go into the harder aspects of this topic because I'm kind of looking for that before my test. The simple parts I get, it's the non- constant acceleration that troubles me
Did you check out the playlists on physics? (There are over 70 of them with close to 2000 videos). They are all in order.
Hi Michael, I wanted to ask you why we have sec, sec^2, sec^3 etc.. same with many other physics quantities where something is squared or cubed what does it mean ? Thanks
If a variable is squared mathematically the order of that variable is raised to 2 also an exponent of zero on a variable is to mean it raised to 1. A second-order variable say in a function if you plot them will result to a curve and not a line. Thus the component 1/2at^2 will result in a curve as our dear teacher has shown.
I understand your lecture than my professor
i have a doubt in my head. in the second segment, to find x2 , a=0 so why time is included?? If a=0 , then the whole 1/2 at^2 should be 0 right ? Anyone clear this up.
There are 3 terms in the equation (not just the (1/2) a t^2 term)
in finding X2, why did you use a different formula than x1
Yisroel Yaakov Grabie
I used the same equation for both
for X2 = X1 + Vt + (the time at which the speed was costant starts from 60s to 240s. which is 180s. if not, explain why?
Based on the description of the problem, the DURATION of the period during which the velocity remains constant is 240 sec (from 60 sec to 300 sec).
This is GREAT! Thanx! 😂
Glad you enjoyed it!
This Gentleman is very kind, because nowadays people even don't fart without fucking money
Very good 🙏🙏🙏🙏
Thank you!
The acceleration is not constant at X1 and X3 so how come you using that equation
That is a good observation. The acceleration is constant over the entire period the train is accelerating, except at the very "end" points of the acceleration. We ignore those for the sake of simplicity as is done in all of lower division physics. If we don't these problems would become much harder as you will see in upper division physics or graduate level physics. Thus in this context it is fine to use that equation. Remain inquisitive, that is great.
What is x?
x represents displacement (distance traveled)
@@MichelvanBiezen thank you so much!
great one
Love the Outfits
very helpful
thanks hey
great video