You guys! I'm so sorry, I screwed up the equation at 5:30, final velocity should be on the left and initial velocity should be on the right. When written out correctly the arithmetic will work out to the number given, however. Sorry about that!
ahmmmm im stupid at p6 so im just gonna ask what youre sayying here is that it must be around 65.4 or something in 5:30 ? am i right XD?? haahah ahaha i also tried to calculate......but anyways a really great help
Professor Dave your'e videos are really informative even our science teacher uses your videos as reference in our whole 4th quarter which is about physics I don't even need my module anymore just your'e videos keep up the outstanding work and hoping for more content in the future. greetings from Tagum City! gikan sa pinakagwapo
its a pity i didnt have you during my high school but am greatfull i have you now in university where we still take physics and chemistry for our molecular biology and genetics bachelor degree
4:03 An alternative to using the quadratic formula is calculating how far the rock will go up, then calculating how long it will take to fall from this height to -100m. Then, the velocity is 0. (This alternative isn‘t strictly better)
3:42 watch your head, bud! that rock is going to hit you! you won't be able to study physics anymore if you get bonked on the head with that rock! oh nooo! :o
You may be my life saver Professor Dave. Yours may be simple but easy to learn as well. Thanks, hope I do well for my quiz tomorrow. (Also the Horizontal Motion is part) I understand the simple mistake on 5:30, but hey mistakes happens. And the answer was still the same when I calculated it. Thanks.
Also at the checking comprehension, can the answer be -321.5 meters, because when I calculated, the result I had was about -321.489 meters, so I just rounded off to the nearest tenths.
I agree with the comment of avoiding the quadratic eq by solving in 2 parts. I got 5.1 meters up in 1.02 sec, now v initial = 0 and drop is -105.1 m. my answers agreed with yours to the hundredth. Otherwise, excellent video. Currently tutoring college nephew, it's been over 45 yrs since I had University Physics.
I'm kinda confused in 2:49 because how did you manage to obtain 4.5s since what I did is (t^2 = 20.4s^2 Don't we just have to square second and time and remove the power so they would be quite equal)??? Since if we didn't square time then it would mean T^2 = 4.5s? which puzzles me.
Dear Pr. I have one question for u ... here is my question:- When a ball is thrown from a top of building upward and reached the ground why the decent velocity isn't negative and why the time in the first case where the ball reach the thrown point isn't considered ?
This is why i love physics its makes your mathematics classes that seem useless and applies them to the real world, to make it feel like all this effort means something, I think that mathematics and physics should be taught as the same class so that the students have an appreciation for the use case of mathematics. Most students that i know never took physics and only Math, and now hate math because the average person is not creative enough to apply mathematics to the real world. That would mean they would have to make these discoveries themselves, that took geniuses to do.
I remember the first time I realised by myself that the equation for time is just a quadratic formula, I was so excited. Really helped in exams being able to write "s=ut + 1/2at^2, so use quadratic formula with t = etc etc" other people would solve for v first and then use v=u+at because it's simpler, but leaves more room for making mistakes and rounding errors
Excuse me Professor Dave, at 5:43 I got a different answer which is -65.4 because I transferred the 10 to the other side, could you please explain how you got your answer for more clarification? thank you so much 💙.
He wrote the wrong equation . On screen it said : Initial Velocity = Final Velocity + Acceleration x Time. However it should have said Final Velocity = Initial Velocity + Acceleration x Time. Use that and you will get the same answer as him.
Professor you are wrong GM ÷ r^2 = total displacement ÷ total time taken ^2 Or g = d ÷ t^2 Answer for your question GM ÷ r^2 = 642 .978m ÷ 8.1sec^2 Therefore , height of the cliff = 642.978m.
The equation reduces to d = 1/2*a*t^2, since the initial velocity and initial position were zero. Given d = 100 m, a = 9.8 m/s^2 and the 1/2 factor, put them all together, and rearrange so t is the subject of the equation and get: t = sqrt(2*d/a) Plug in the data: t = sqrt(2*100/9.8)
The value of g is always negative. It does not change according to the motion of an object. Objects moving downward are moving in the negative direction.
Other UA-cam site's including my sir are saying that the value of g for objects moving downwards is approximately 10m/S2 while for objects moving upwards is approximately -10m/s2
Professor, if we use postion vector where origin at the man throwing the stone and pointing to the rock, during the process, the position vector is zero when rock travel back to which the man sits and going further down to ground. The position vector finally becomes - 100 m .
My prof told me "If the object goes upward, the acceleration due to gravity is negative then Positive if downward" because gravitational pulls downward with the acceleration of constant (9.81m/s).
Professor Dave can you show me the whole solution on how did you get the time on the vertical solution when the initial velocity has a value and how you get the unit?? please
if you are having trouble with basic algebra, you will have to go to my algebra playlist and review the fundamentals. this series assumes basic ability in algebra.
Professor : *Teaches us with the best content possible for free, and then says "thanks for watching"* Me : We're so going to hell! Jokes apart, thanks a lot sir; I really appreciate your work! It has helped me a lot.
You guys! I'm so sorry, I screwed up the equation at 5:30, final velocity should be on the left and initial velocity should be on the right. When written out correctly the arithmetic will work out to the number given, however. Sorry about that!
Professor Dave Explains thank you, I was going crazy for a bit lol
That explains why. Whahaha thank you
my lord. had my wife and son trying to figure out the math on that one. Thought I was going crazy!!
all people made mistakes
ahmmmm im stupid at p6 so im just gonna ask what youre sayying here is that it must be around 65.4 or something in 5:30 ? am i right XD?? haahah ahaha i also tried to calculate......but anyways a really great help
I like that statement," we tend to spend most of our time of earth."
That stood out to me aswell.
_The ISS crew has entered the chat ..._
Is we tend to spend most of our time on the Earth,not of the earth
😂😂😂😂😂😂😂😂😂
This video is meant for long time validity it seems lol
Thanks!
Bro casually donated 10$
I'm not even learning this in school right now but I still watch these to learn new things!
that's what i'm hoping many more will do! lead the way!
Who the fuck does that
@@thefisherman9553 so you know all 7 billion people in earth?
Same XD
What grade are ya? Me grade6
bro you are literally so amazing man. Strugglig for the past week on kinematics and now I understand it in less than an hour. Subscribed.
PROFESSOR DAVE MAHH MAYYNN saving me in chem last year and saving me in physics this year
me too ;-;
Same! honestly couldn't have done this without him.
professor at rescue :)
Professor Dave your'e videos are really informative even our science teacher uses your videos as reference in our whole 4th quarter which is about physics I don't even need my module anymore just your'e videos keep up the outstanding work and hoping for more content in the future. greetings from Tagum City! gikan sa pinakagwapo
its a pity i didnt have you during my high school but am greatfull i have you now in
university where we still take physics and chemistry for our molecular biology and genetics bachelor degree
4:03 An alternative to using the quadratic formula is calculating how far the rock will go up, then calculating how long it will take to fall from this height to -100m.
Then, the velocity is 0.
(This alternative isn‘t strictly better)
it is.
@@BBCxJEANHow?
in this way why my time is 4.63 sec while in the video it is 5.65
@@Firnas_7 Need to add the time rock is in air for the initial upward motion (I got 1.02 sec plus the 4.63 sec =5.65 sec)
Thank you so much professor Dave
Literally save so much time and gained more knowledge than a whole month of spending of kinematic at my college. WOWW
Relearning physics and math at seventy-five 3:44 creates order internally. After the election, I need that.
Wow! How is it sir, have you been making nice progress?
Napped for a week and missed everything, watched this at 2am the day before the test, and then proceeded to finish first and get a 100. Luv u dave ❤
3:42 watch your head, bud! that rock is going to hit you! you won't be able to study physics anymore if you get bonked on the head with that rock! oh nooo! :o
You may be my life saver Professor Dave. Yours may be simple but easy to learn as well.
Thanks, hope I do well for my quiz tomorrow.
(Also the Horizontal Motion is part)
I understand the simple mistake on 5:30, but hey mistakes happens. And the answer was still the same when I calculated it.
Thanks.
Also at the checking comprehension, can the answer be -321.5 meters, because when I calculated, the result I had was about -321.489 meters, so I just rounded off to the nearest tenths.
Hi Dale.
I like that you put a comprehension question in the end which helps us to revise the topic we have just learnt from you,Love you Dave,Stay Awesome.😊
you are the cause to love physics thanks
the cliff is -321.489 m tall🗿
(since it is a cliff the length can not be negative number so that is why it becomes 321.489)
I agree with the comment of avoiding the quadratic eq by solving in 2 parts. I got 5.1 meters up in 1.02 sec, now v initial = 0 and drop is -105.1 m. my answers agreed with yours to the hundredth. Otherwise, excellent video. Currently tutoring college nephew, it's been over 45 yrs since I had University Physics.
Your videos are just awesome
Thank you very much! This made it a lot easier to understand 😄.
I'm kinda confused in 2:49 because how did you manage to obtain 4.5s since what I did is (t^2 = 20.4s^2 Don't we just have to square second and time and remove the power so they would be quite equal)??? Since if we didn't square time then it would mean T^2 = 4.5s? which puzzles me.
you do √20.4 not 20.4*20.4
that feeling of dread when you instantly realize you forgot how to multiply decimals
Once again you have saved my future, thanks for making this look easy because it really is.
I saw professor dave whipping a model x performance not too long ago in san Diego. I'm glad he's doing good. He deserves it
I don't know what this means.
@@ProfessorDaveExplains he saw you driving a testla in san diego
@@artzmasterz5647 Well that didn't happen so it must be a doppelganger.
"But with vertical motion, down will always be negative.” sobs in gdscript
Thank you for all your beneficial high quality videos. I often mirror many of your physics videos in most of my lessons to my students .
Thank you for the information Professor Dave! Very helpful in my science class.
sir i am really impressed by your videos.these are really helpful
Dear Pr. I have one question for u ... here is my question:-
When a ball is thrown from a top of building upward and reached the ground why the decent velocity isn't negative and why the time in the first case where the ball reach the thrown point isn't considered ?
This is why i love physics
its makes your mathematics classes that seem useless and applies them to the real world, to make it feel like all this effort means something, I think that mathematics and physics should be taught as the same class so that the students have an appreciation for the use case of mathematics. Most students that i know never took physics and only Math, and now hate math because the average person is not creative enough to apply mathematics to the real world. That would mean they would have to make these discoveries themselves, that took geniuses to do.
I remember the first time I realised by myself that the equation for time is just a quadratic formula, I was so excited. Really helped in exams being able to write "s=ut + 1/2at^2, so use quadratic formula with t = etc etc"
other people would solve for v first and then use v=u+at because it's simpler, but leaves more room for making mistakes and rounding errors
When you changed the variables from the original ones it completely confused me.
you are a lifesaver. Thank you
Sir I am a big fan of you ,your way of teaching is awesome and so simple that one can easily understand everything😊😊👌👍
Nice work Sir
I loved the introoo
PROFESSOR DAVE I LOVE YOUU😫
thanks this video really helped me
Excuse me Professor Dave, at 5:43 I got a different answer which is -65.4 because I transferred the 10 to the other side, could you please explain how you got your answer for more clarification? thank you so much 💙.
yea i got the same answer, i cant understand why it is that way
Dude please same why did he flip equation!!!
He wrote the wrong equation . On screen it said : Initial Velocity = Final Velocity + Acceleration x Time. However it should have said Final Velocity = Initial Velocity + Acceleration x Time. Use that and you will get the same answer as him.
He did not wrote the equation wrong. The answer is simply wrong. He used Vi=Vf+at to find Vf. Use algebra.
God bless you Dave.
thank u so much prof, for such a brief explanation. i
Thanks Prof, you the best
❤❤❤❤keep up the good work you legend❤❤❤❤❤
Thank you!
3:20 is FIRE
Fantastic!
Am very thankful to my sister for suggesting me to see this video 😊
Hi! Help me understand how did you get the 4.5 from the -100 and -4.9
don't forget to take the square root!
sir thanks for your awesome videos
i have a question in 2:51 did you just divide it to get the value of t?
thankyou so much
Thank you
sorry but i cant get how how -4.9x² + 10.0x + 100 becomes 5.65 the answer
quadratic formula
With the quadratic formula my answers were reversed my positive was 3.6 seconds and my negative was -5.65. I am also confused
omg i love u so much actually
so nice guy and good explanation
Professor you are wrong
GM ÷ r^2 = total displacement ÷ total time taken ^2
Or g = d ÷ t^2
Answer for your question
GM ÷ r^2 = 642 .978m ÷ 8.1sec^2
Therefore ,
height of the cliff = 642.978m.
"SCP 5094 is not real"
professor dave: hold my beer
I think the formula at 5:36 should be Vf=Vi+at not Vi=Vf+at? Maybe I'm wrong?
oh no! what a stupid mistake :( thanks for catching that!
Hey it made me look into it in more depth so it's drilled into my head now haha :p You can probably just shove an annotation box over it
So would the answer be -44.88m/s instead? Please if you could reply that would help alot, just to make sure I actually understand!
Ok thanks very much sir!😊😊
2:51 how time=4.5? sorry if this is a dumb question im quite new to physics
The equation reduces to d = 1/2*a*t^2, since the initial velocity and initial position were zero.
Given d = 100 m, a = 9.8 m/s^2 and the 1/2 factor, put them all together, and rearrange so t is the subject of the equation and get:
t = sqrt(2*d/a)
Plug in the data:
t = sqrt(2*100/9.8)
watching here sir
Gravitational acceleration for objects moving downwards is +9.8m/s2 not -9.8m/S2 this value is for objects moving upwards
The value of g is always negative. It does not change according to the motion of an object. Objects moving downward are moving in the negative direction.
No sir gravitational acceleration for objects moving upwards is -9.8ms-2 because it is moving against the gravity
Again, it’s always negative.
Why the gravitational acceleration for objects moving downwards is -9.8m/S2 please justify it sir
Other UA-cam site's including my sir are saying that the value of g for objects moving downwards is approximately 10m/S2 while for objects moving upwards is approximately -10m/s2
LAMAT KAAYO PROF. DAVHEE
Thank you!!!
Professor, if we use postion vector where origin at the man throwing the stone and pointing to the rock, during the process, the position vector is zero when rock travel back to which the man sits and going further down to ground. The position vector finally becomes - 100 m .
THANK YOU THANK YOU THANK YOU!!!
I think we need to add the time of object thrown upward and the time of object when fallen to the ground.
It's all done in one calculation. There is only one force acting upon the object.
You could make down positive as long as you make up negative
thanks
This video is really helpful :)
Im from 🇵🇭 thank you professor Dave
Crush gud ni maam escuadro si professor dave explains
My prof told me "If the object goes upward, the acceleration due to gravity is negative then Positive if downward" because gravitational pulls downward with the acceleration of constant (9.81m/s).
Acceleration due to gravity is always negative. It pulls in the negative direction.
5:03 i cant understand at this point...how can u know where to assign the numbers
Ty I hope that this helps me in class tommorow 👏😄
Professor Dave can you show me the whole solution on how did you get the time on the vertical solution when the initial velocity has a value and how you get the unit?? please
the one with the quadratic equation? check out my mathematics tutorial on that subject if it's confusing!
Okay thank you Professor Dave..
Professor Dave i have a question why does the unit disapper??
For the equation at 1:46, should there not be a initial position at the right hand side of the equation?
am really appreciate u.........tanx in advance
5:43 Isn’t it v= u + at?
why for formula Vf = Vi +2ad is sometimes Vf2 = Vi2 +2ad?? Great channel by the way
It's squared for both equations. The first copy of that equation is incorrect.
for the first problem, why did we not take into account the initial position of the rock?
How was the quadratic equation applied in the first equation 5:36
How can we solve horizontal velocity when an object fall vertically
Thank youuuuuuu
Hi sir, how did you get the 4.5 s at 2:48, I still can't figure it out how you got it
if you are having trouble with basic algebra, you will have to go to my algebra playlist and review the fundamentals. this series assumes basic ability in algebra.
3:42 simple way to get hurt lol
Funny I laughed
for the second the final velocity should be 65.37 because we had to add it over to the other side. right?
oh no, i think i put vf and vi in the wrong spots! the number in the answer is correct, but i seem to have screwed up the equation :(
Thank you! I was driving myself crazy over this.
Thanks great video😊..but How to find its highest point and time at the highest point?
Is there any other way of solving that without using the quadratic formula?
Hey Professor Dave, isn't upward motion for gravity -9.8m/s while downward motion is +9.8m/s? I'm very confused.
Acceleration due to gravity is independent of the motion of any object, it's always negative because gravity always pulls things down to the ground.
Can we use this videos for a levels?
Professor : *Teaches us with the best content possible for free, and then says "thanks for watching"*
Me : We're so going to hell!
Jokes apart, thanks a lot sir; I really appreciate your work! It has helped me a lot.
im stucked in 2:42. how'd you get the 4.5s?
wtf, are you dumb or are you joking? 100/4.9=20.4, √20.4=4.5
Where is the time which take up ward ? We should solve it in the formula of vf=vi +at
It helps me a bit to understand
But thanks it was helpful
Thanks Physics Jesus
Need an explanation about, is 'g' is negative or positive when object is fallen on the ground?
g is always negative by convention
I have a question, where did the 0.5 came from again?
1/2
@@ProfessorDaveExplains oh thanks Professor!
the way i studied if i throw something down the g value is positive
how did you get 4.5s on the first problem, sir?
Hello Professor Dave. Do you have an explanation about 3-dimensional motion?