How Lawn Mower Blades Cut Grass (at 50,000 FRAMES PER SECOND) - Smarter Every Day 196

  • Published: 01 July 2018
  • For $30 off your first week of HelloFresh, visit and enter "smarter"!
    Please subscribe if this video earned it:
    ⇊ Click below for more links! ⇊

    High Resolution images will be provided to the Patrons of Smarter Every Day at:

    Check out the interview with Rodney on the 2nd channel:

    People don't tweet me their thoughts about videos enough. I'd love to hear from you.

    Smarter Every Day on Facebook

    Smarter Every Day on Patreon

    Smarter Every Day On Instagram

    Smarter Every Day SubReddit

    Song “Adze” and “Spins” by Gordon McGladdery of A Shell In The Pit
    Listen to it on Spotify: (It helps
    All A Shell in the Pit music available at:



    The thought is my efforts making videos will help educate the world as a whole, and one day generate enough revenue to pay for my kids college education. Until then if you appreciate what you've learned in this video and the effort that went in to it, please SHARE THE VIDEO!

    If you REALLY liked it, feel free to pitch a few dollars Smarter Every Day by becoming a Patron.

    Warm Regards,


  • Science and Technology Science and Technology

Comments • 10 750

  • ZetPerson
    ZetPerson  2 years back

    At 6:03 my stepdad walked in and told me to go mow the front yard

    • 1000 subs with no videos
      1000 subs with no videos  1 months back


    • Jake
      Jake  1 months back

      Hi Jack who tf asks that it’s none of your business

    • Daniel Huddleston
      Daniel Huddleston  2 months back

      Sooo now you just need to explain a scythe

    • Miguel M
      Miguel M  7 months back

      Sad you didn't grow up with your biological father

  • Matthew Rowe
    Matthew Rowe  24 hours back

    Now explain a scythe!

    • Chewie576
      Chewie576  2 days back

      You got a video on Weed Whackers? Or the Aussies call them Whipper Snippers.

      • Wayne Vessell
        Wayne Vessell  3 days back

        I work at a golf course.

        • Wayne Vessell
          Wayne Vessell  3 days back

          Look into how a hover mower works and how it cuts grass.

          • damage control
            damage control  4 days back

            It appears your blades are dull and/or your blade speed is pretty slow.

            • George Judd
              George Judd  4 days back

              No sound

              • Bill C
                Bill C  1 weeks back

                Perhaps you should do a wind tunnel experiment with smoke streams over the blade to visualize the upward lift in front of the blade. You could also ask, would your lawnmower cut grass in a vacuum?

                • Sydney
                  Sydney  1 weeks back

                  I didn’t know I needed this video in my life. 🤔😂

                  • johnnyh996
                    johnnyh996  1 weeks back

                    Having the physics explained was pretty neat, but the verse out of 1 Peter 1:24 caught my attention the most. I'm kinda wondering the exact reason why that exact scripture was chosen and added in the end...

                    • JNS Studios
                      JNS Studios  1 weeks back

                      Who else thought this was the SloMo Guys?

                      • Gerry Collins
                        Gerry Collins  1 weeks back

                        Those blades are powered by a P.T.O (Power Take Of Shaft) taken from a tractor and powered by the engine and it spins at 540rpm to 1,000rpm (revolutions per minute) or to simplify it it spins around at 540rpm to 1,000

                        • Brandon Collins
                          Brandon Collins  1 weeks back

                          Rodney!!!!! Good dude!! He is a blessing to many!!!

                          • Truck Mann
                            Truck Mann  2 weeks back

                            Show slow no on a chain saw

                            • skillilliyan
                              skillilliyan  2 weeks back

                              or it smacks it and pulls it taught and hits it again before the taughtness is released

                              • skillilliyan
                                skillilliyan  2 weeks back

                                do lawnmovers make good succ?

                                • MrKFahn
                                  MrKFahn  2 weeks back

                                  Not exactly a 'lawn' tool per se, but how about a chainsaw episode?

                                  • Sairight
                                    Sairight  2 weeks back

                                    Not to dispute the presence of a lift caused by the airflow, I would still like to see if/how well would be grass cut by a blade with that endpiece producing the lift cut off. I don't believe the airflow is the main reason - it might be also by the structural-strenght of the grass itself

                                    • Geo
                                      Geo  2 weeks back


                                      • Nomi Malone
                                        Nomi Malone  2 weeks back

                                        Lawn tools series ideas:
                                        - electric hedge trimmers
                                        - weed whacked
                                        - rotary style unpwered mowers.

                                        • REGIER BROS
                                          REGIER BROS  2 weeks back

                                          1:18 It's called a swather/ windrower

                                          • Ross Clapper
                                            Ross Clapper  2 weeks back

                                            if you didnt tighten a lawnmower blade and then the lawnmower flipped over, would the blade fly away?? i always wished the mythbusters did this but you should try!!

                                            • Eloy Sosa
                                              Eloy Sosa  2 weeks back

                                              I just thought it was pure force and speed that cut the grass, I would cut long pieces of grass with a long stick and just figured lawnmowers were a mechanized version of that lol

                                              • Eat Westy
                                                Eat Westy  2 weeks back

                                                What about old school reel mowers? They are still relevant as well as hover mowers

                                                • Christo du Plessis
                                                  Christo du Plessis  3 weeks back

                                                  I guess I am nothing like Destin then, I have never thought about how a lawnmower blade interacts with grass 😕

                                                  • Ethan Gao
                                                    Ethan Gao  3 weeks back

                                                    her: he's thinking about someone else
                                                    him: *wonders about how lawn mowers work*

                                                    • mind fornication
                                                      mind fornication  3 weeks back

                                                      So, they built these type of mowers in the 50s, before hi speed cameras......were people then super genious ???

                                                      • Noah
                                                        Noah  3 weeks back

                                                        How do those old style lawn mowers work? Like the round ones, that don't have any kind of motor

                                                        • Robert Thomas
                                                          Robert Thomas  3 weeks back

                                                          Young me swinging my foam sword fast enough to cut grass

                                                          • A horse with No Name
                                                            A horse with No Name  3 weeks back

                                                            1:22 it’s called a sickle bar mower.

                                                            • youssef toba
                                                              youssef toba  3 weeks back

                                                              Vegan will be crying 3:10

                                                              • Georgia Boy 76
                                                                Georgia Boy 76  4 weeks back

                                                                Who else didn't know what the bent up part on the lawnmower blade was for?

                                                                • sam michaels
                                                                  sam michaels  4 weeks back

                                                                  You gotta file down that bent blade and compare a flat one to a bent one. 🤷🏻‍♂️🤷🏻‍♂️🤷🏻‍♂️🤷🏻‍♂️🤷🏻‍♂️

                                                                  • Mathieu Grondin
                                                                    Mathieu Grondin  4 weeks back

                                                                    How does a chainsaw tooth rips off a chip of wood ?

                                                                    • Daniel Ginther
                                                                      Daniel Ginther  1 months back

                                                                      The debris exiting the cutout you made defeats the engineered design of the deck and blade. People who sharpen the top and bottom of the blade are also defeating the vacuum intent of the blade design.

                                                                      • Kyle Baricz-Ives
                                                                        Kyle Baricz-Ives  1 months back

                                                                        Hey love your channel! You should shoot a chainsaw cutting in slow motion, it'd be really awesome to see! Especially if you like woodworking! 🤙

                                                                        • The pigs 987
                                                                          The pigs 987  1 months back

                                                                          8:18 his neck looks like satsiki

                                                                          • Andy
                                                                            Andy  1 months back

                                                                            A lawnmower could cut grass without requiring the air flow properties. A weedwacker cuts grass just fine without any lifting effects and with a relatively dull trimmer string. The air flow in the lawnmower is more for lifting the grass for a more uniform cut and to expell the clippings.

                                                                            • Paul Weger
                                                                              Paul Weger  1 months back

                                                                              and why does a handheld lawnmower with strings work ?

                                                                              • Ian Bast
                                                                                Ian Bast  1 months back

                                                                                imagine how itchy you were after the intro

                                                                                • T. Rose
                                                                                  T. Rose  1 months back

                                                                                  Slow mo chainsaw, there is a lot of physics in a saw, chain pitch, width, rpms.

                                                                                  • David Zachmeyer
                                                                                    David Zachmeyer  1 months back

                                                                                    Weed trimmers cut grass without updraft.

                                                                                    • Robert Siefert
                                                                                      Robert Siefert  1 months back

                                                                                      Love that Rodney Smith Jr from Raising Men Lawn Care made a cameo

                                                                                      • Paul Bilobrowka
                                                                                        Paul Bilobrowka  1 months back

                                                                                        A weed eater would be awesome!!!! It only has a string and no airflow to pull the grass up.

                                                                                        • Bigby White
                                                                                          Bigby White  1 months back

                                                                                          Do a vid where you compare the slow mow of weed whip lines. Like standard rounded wire versus shaped and sharped edged wire

                                                                                          • John Dunn
                                                                                            John Dunn  1 months back

                                                                                            Another word for physics-overthinking

                                                                                            • Grey in Grey
                                                                                              Grey in Grey  1 months back

                                                                                              1:59 RIP Scissors :(

                                                                                              • AfterMyReawakening
                                                                                                AfterMyReawakening  1 months back

                                                                                                Breaking news
                                                                                                NASA physician cannot figure out law mower physics.
                                                                                                There must be a secret physic syndicate that knows it all and does not teach the world the true power of the one world formula