Measure height with a watch! Cliff jump science

  Shikime 2,505,008

Mark Rober

6 vjet më parë

This is a simple trick using high school physics where you can measure the height of really tall objects like a cliff, using just a stopwatch.
Special thanks to Active Life Store for the GoPro shots. You can get one from them here:
Here is a link to the FREE app (free as in FREE, as in I don't even have any ads in it or make any money off of it whatsoever) in the app store (sorry, no android at this time):

I make videos like this once a month all year long while supplies last:
FACEBOOK ME: MarkRoberALnets

All music created by Qwiet. You should go sub his channel:
Twitter: qwiet
Facebook: qwiet

Ryan Roberts
Ryan Roberts 17 orë më parë
He does cuss when properly agitated!
Rilakkuma's cookie
Rilakkuma's cookie 2 ditë më parë
what happens if you use different force on the objects that fall?
Tanner Henry
Tanner Henry 3 ditë më parë
2:05 Thanks for including Tanooki Mario! Doesn't seem like the other 2 objects though. Mario logic.
Fenrir _odinson
Fenrir _odinson 6 ditë më parë
Ai The Only One WATCHING this In 2020
IPhone gamer
IPhone gamer 8 ditë më parë
hey Mark, if you see this comment, can you put your app on Play Store please? (if you ask, I love doing video archeology sometime)
Justine Kent Smith09
Justine Kent Smith09 14 ditë më parë
Wait the weight?????
Mason Clews
Mason Clews 17 ditë më parë
Dishant Deepak
Dishant Deepak 19 ditë më parë
Ruining ALnetsrs' lives since 2013
Marco 21 ditë më parë
The only guy verifying cliff jumps
Eelco Frans
Eelco Frans 23 ditë më parë
2014 nah2015 nah 2016 nah 2017 nah 2018 nah 2019 nah 2020 yes he waited enough
Vada 26 ditë më parë
"How 'bout that!" -man of science in an extremely deadly enviornment.
Melalaine Cobico
Melalaine Cobico 27 ditë më parë
2:54 Nice
TheBlueBanana 97
TheBlueBanana 97 27 ditë më parë
True fact: you have no idea what he is saying half the time Also true: you click on his videos anyway
Rok Krmelj
Rok Krmelj 27 ditë më parë
start using metric system first.....
Ayman J97
Ayman J97 28 ditë më parë
nice voice over XDXDXD
Nitroxitation 28 ditë më parë
3:35 Mark Rober sounded like he swore
Avon Junior Primary
Avon Junior Primary Muaj më parë
you're the greatest nobody can defeat you
Noelle Maynard Holmes
Noelle Maynard Holmes Muaj më parë
Tom A
Tom A Muaj më parë
Stop using cheap clickbaits and ancient units of measurement (or at least provide both), and I will subscribe to your channel again.
idontneedaname85 Muaj më parë
0:01 you are welcome
Benjamin Tran
Benjamin Tran Muaj më parë
0:30 took not taked cmon rober
AlphaChalices451 Muaj më parë
You really got him there Benjamin Tran!
Ella B
Ella B Muaj më parë
My iPad didn’t like this audio 2:07
AlphaChalices451 Muaj më parë
Matthew Johnson
Matthew Johnson Muaj më parë
I was thinking, "OK, 9.81 m/s^2 acceleration" and then you said "16" and I immediately was disappointed in you for not teaching your ALnets fans to use standard SI measurements :)
AlphaChalices451 Muaj më parë
Meganeura Dunn
Meganeura Dunn Muaj më parë
Only if I knew this when I went caving, then I would know how deep the endless pit is
Quinn Moore
Quinn Moore Muaj më parë
Downloaded the app strait away
digital Friday
digital Friday Muaj më parë
Sahil Sahebzada
Sahil Sahebzada Muaj më parë
Bro on Christmas my wish is that I can be smart as him I wishhhhhhhhhhhhh
AlphaChalices451 Muaj më parë
Work for it. It isnt as much as how naturally talented you, its how much effort you put into your education. And its not a tell myself and I am, you have to put in the boring hours of learning if you want to succeed
WichtigerNoSkin Muaj më parë
What is 48ft in an actual measurement?
Luke Duckworth
Luke Duckworth Muaj më parë
Who watching this in 2020
AlphaChalices451 Muaj më parë
Harry Coupe
Harry Coupe Muaj më parë
He sounded so different
OneHitWarrior1 Muaj më parë
1:58 "how bout that" 😂😂😂
Christopher Stewart
Christopher Stewart Muaj më parë
I LOVE you Mark
Jaco Ja
Jaco Ja Muaj më parë
But... But this video wasn't planned 8 months ago 🤦🏻‍♂️
boudiemation Muaj më parë
americans am i right
AlphaChalices451 Muaj më parë
Biaka Muaj më parë
Nice learned something new today.👍
Oasis Spida
Oasis Spida Muaj më parë
Me and my friend judged that the Empire State Building is 381 m tall. Rest In Peace terry
AlphaChalices451 Muaj më parë
Jab jab power dunk
Universum Muaj më parë
The air resistance was not taken into account.
AlphaChalices451 Muaj më parë
Yes it is not 100 percent accurate. He acknowledge this
Akiboiii Muaj më parë
me telling my friends i like to watch Mark Robers Videos They saying hes a nerd me saying that i dont care if hes a nerd (hes not) i just think its cool that hes so frickin smart.
AlphaChalices451 Muaj më parë
Being smart is an effort. Mark Rober has a ton of effort and passion in what he does
Koliha Jonáš
Koliha Jonáš Muaj më parë
The apps told me that planes are in the space :O
ian mafnas
ian mafnas Muaj më parë
the time in youtube vidios are diffrent in real life
Batbot2006 Muaj më parë
But it depends on if they jump,fall or get accidentally-on purpose pushed off the cliff
Batbot2006 Muaj më parë
Biaka For ... science
Biaka Muaj më parë
Why would you time someone who falls or accidentally on purpose pushed off the cliff, just to know the height.
parmesian Muaj më parë
when you used imperial rather than metric, that hurt. nasa themselves lost a $125 million mars orbiter because they measured everything in imperial units but everyone else used metric. the us needs to convert to metric imo, it’s so much easier to understand
Tristan Le-oviso
Tristan Le-oviso 2 muaj më parë
How did I learn this in like 7 seconds (Nobody thought me this till now)
Maise cloudy Girl
Maise cloudy Girl 2 muaj më parë
I’m only six years late
Juan Motorsports
Juan Motorsports 2 muaj më parë
Lol 61’ wawawawawaaaaahhhh
Legendary Lime
Legendary Lime 2 muaj më parë
Now this is a new way to discover how high my skyscraper is.
Productivity 2 muaj më parë
ew feet
Brooke Simons
Brooke Simons 2 muaj më parë
I didn’t even understand any of that math lol
Brooke Simons
Brooke Simons 2 muaj më parë
If you simply Abidjan is+\^\^£\¥]¥]€ you get ajdhej*{*]^]] then you do complicated math I’m gonna talk about like it’s basic addition
egame1122 2 muaj më parë
Mark Rober: * realeases app * The News: Number of people struck by falling rocks mysteriously skyrockets
Der Tuk
Der Tuk 2 muaj më parë
i was out when he spoke about feet.
- oStoomp -
- oStoomp - 2 muaj më parë
Oh my god he used feet instead of bald eagles by quarter pounder. How are we supposed to write this down?
Johannes Wing
Johannes Wing 2 muaj më parë
What if you drop a rock and you don't hear anything until you pass that same hole 2 weeks later
mark wohlert
mark wohlert 2 muaj më parë
Love the shirt!! Chive on
william chen
william chen 2 muaj më parë
For those that are confused at why 16, it's because the unit is in feet, whereas the normal kinematic equation would give you unit in meters
Optic Axis
Optic Axis 2 muaj më parë
If you can't see the bottom of the cliff I suppose you could just push someone off and then use this equation: 16 x LengthofScream²
Ryan Davies
Ryan Davies 2 muaj më parë
App doesn't work for androids?
carolina carlos
carolina carlos 2 muaj më parë
carolina carlos
carolina carlos 2 muaj më parë
carolina carlos
carolina carlos 2 muaj më parë
carolina carlos
carolina carlos 2 muaj më parë
carolina carlos
carolina carlos 2 muaj më parë
Daniel Guzman
Daniel Guzman 2 muaj më parë
Jajajajajaja yo pensando como asi que 16...jajajaja pinche sistema inglés
Adrian Ryberg
Adrian Ryberg 2 muaj më parë
you get a like for David Scott clip alone
leinadkk 2 muaj më parë
YES lets all use feet, inches, thumbs, toes, arms and what ever other bullshit you follow Americans decide is a good system to measure stuff....
Hatim Rajib
Hatim Rajib 2 muaj më parë
Feet 🤮
Pep Medina
Pep Medina 2 muaj më parë
But how much depth do we need dependong on the height?
Daanvip123 2 muaj më parë
Could you update this app please
p14zm4 2 muaj më parë
Oh cool, I'm gonna measure the hight of this bridge now
FoxTales 2 muaj më parë
Hey what are some survival tips that could help someone that involve science? Idk if you’ve seen the Disney movie a wrinkle in time but theres a scene in the movie where the girl does physics in a matter of seconds to save her and her friend from a storm throwing branches and other things over a wall i was wondering if there was something like that ?
Rickle Pick
Rickle Pick 2 muaj më parë
Where does the 16 come from? If you fall for 1 second, you will have traveled 31.85ft or 9.8 meters
Skate Or Die
Skate Or Die 2 muaj më parë
no self respecting scientist would use feet as a measurement for distance
Rickle Pick
Rickle Pick 2 muaj më parë
ExaltedwithFail 2 muaj më parë
So if it takes 200 seconds of falling we get 200x200 so 40k and then we do 40k x 16 for 640k for the height. Seems a bit off since thats 195km - Maybe i did something wrong but the simplification seems wrong since that would be needing someone to fall from low orbit at 1km per second to the floor
Tbird 2 muaj më parë
why are you here after 6 years?
WoodScrape Woodcraft
WoodScrape Woodcraft 2 muaj më parë
I always learn from you Mark. Thank you
Oliver’s games, trains and model railways
Oliver’s games, trains and model railways 2 muaj më parë
London Underground stuff I am English but I don't live in London but I have been to London. I have a train company Logo from the North which is Northern Rail
Stan Childs
Stan Childs 2 muaj më parë
I came for the girls in bikinis. Screw science.
Han Boetes
Han Boetes 2 muaj më parë
What size is the imperial foot?
Douger Rohmer
Douger Rohmer 2 muaj më parë
I love your content, but should point out that Newton would have done this calculation in meters, because he was a genius. :-)
Douger Rohmer
Douger Rohmer 2 muaj më parë
@Rickle Pick Do you really want me to pull out my nanometers?
Rickle Pick
Rickle Pick 2 muaj më parë
@Douger Rohmer i agree, but the difference between 1 inch and one foot is smaller than the difference between 1 cm and 1 meter.
Douger Rohmer
Douger Rohmer 2 muaj më parë
@Rickle Pick *wheels in centimeters and millimetres* No, they are not.
Rickle Pick
Rickle Pick 2 muaj më parë
@Douger Rohmer feet are more precise than meters.
Douger Rohmer
Douger Rohmer 2 muaj më parë
@Rickle Pick Meters ARE for scientists. And linguists.
Doktor Dok
Doktor Dok 2 muaj më parë
Dude, just use metric...
Georg 2 muaj më parë
the app needs an update!
Renzo Fernandini
Renzo Fernandini 2 muaj më parë
science and feet shouldn't meet
Mason Ditmars
Mason Ditmars 2 muaj më parë
First, throw the watch then count how long until it hits the water.
Luis Mijangos
Luis Mijangos 2 muaj më parë
Excellent video, as usual, Mark. Two comments: I had problems with that equations for drops with fall time measurements lower than 1.2 s aprox because of the reaction time. Typically, when you are alert and sober, your body takes like 0.2 s between the brain sending the signal and your thumb pushing start and stop.
1 2
1 2 2 muaj më parë
Why does it say over 19 million views at 3:23 on top off the screen
RamesGamesLC 2 muaj më parë
@joker102877 over 1 billion now
joker102877 2 muaj më parë
That's his total channel views at the time of the making of this video.
Cz 2 muaj më parë
Is this near San Diego?
Golf Nut
Golf Nut 2 muaj më parë
I think this is cool, but there is no frickin' way I am jumping off a 48' cliff!!!
Stick Mann
Stick Mann 2 muaj më parë
*how about that?*
Tey Treet
Tey Treet 2 muaj më parë
Feet? Feet? Really?
Mateo Thomsen
Mateo Thomsen 2 muaj më parë
here in 2020
Bot reporter.
Bot reporter. 2 muaj më parë
Aditya Nugroho
Aditya Nugroho 3 muaj më parë
sorry but i think you are using feet
Daniel Dai
Daniel Dai 3 muaj më parë
Problem is, you won’t know until you’ve jumped
Nicholas 3 muaj më parë
I could slow down the video?
R3dPanda13 3 muaj më parë
1:07 now its going to be easier in math class
Life at Its Finest
Life at Its Finest 3 muaj më parë
What about terminal velocity? Objects don't fall at the same speed the whole time so does the equation take this into effect? It can't right?
3Ca6le0 3 muaj më parë
To prefect your results dividere the resultat with what ever the person reaktion time is fx 0,343
Mocile 3 muaj më parë
Oh we clickbaiting now
Andreas Buder
Andreas Buder 3 muaj më parë
I somehow thought before watching, he was calculating the height of the people jumping^^
Jacob Stern
Jacob Stern 3 muaj më parë
can you explain why the equation simplifies to 16t^2? I know about the 3 kinematic equations and I have seen some equations with 16t^2 but I never knew why gravity on earth boils down to that
Max Ellas
Max Ellas 3 muaj më parë
Imagine going to the moon to drop a hammer lmao
Jw 3 muaj më parë
i have a easier way to do it just push your friend off and if they survive it is good to jump and if they get injured or die don't jump
Fake Justin Y.
Fake Justin Y. 3 muaj më parë
Who else never knew about this video?
Micco Sicco
Micco Sicco 4 muaj më parë
Legend has it, a man turned the timer on, and lumpwd off a cliff... And the timer was never turned off
stealthy panda
stealthy panda 4 muaj më parë
Compare this 3 min and 36 sec vid to how long this would of took to learn this in school
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