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

  • Published: 01 July 2018
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  • Science and Technology Science and Technology

Comments • 10 729

  • ZetPerson
    ZetPerson  1 years back

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

  • trumanhw
    trumanhw  1 days back

    *It's a flowbee*

    • FaithfulYoshi
      FaithfulYoshi  3 days back

      3.1K grasshoppers disliked this video.

      • Rafael Infante
        Rafael Infante  4 days back

        weed wacker
        And trencher

        • BEAU OSTROM
          BEAU OSTROM  5 days back

          Also when you spray it out it is sucking the grass up so it is standing up so can cut it.

          • Anas Iftikhar
            Anas Iftikhar  6 days back

            Hey Destin. Greetings from Pakistan. Great content man.
            You use high speed camera for the blockbusters. How about a video on "how high speed cameras work?".
            You can cover frames per second, human eye update rate, high speed camera tech, frame grabber etc etc and etc...

            • Rami Negev
              Rami Negev  6 days back

              I beleive that it is really just the speed of the blade that cuts the grass. If the blade was moving any slower then the blades of grass simply get pushed over, but if the blade is moving faster then the blade of grass simply cannot get pushed out of the way by the mower blade and the mower blade goes through the blade of grass. It is a matter of momentum. As well, if the Mower blade was sharper, it would not need as much speed to cut the grass - I could seein the high speed video how the mower blade passed over some grass bladed several times before it would "bite" into the blade of grass and actually cut it. Effecively the Sharp mower blade provides more friction to the grass and the grass blade cannot slide out of the way.
              I think the only real way to test the Air Flow Theory is to replace the hole on the side of the mower with a Plexyglass side and film it that way.

              • MJ Young
                MJ Young  1 weeks back

                Video shows that its 20% cutting and 80% tore. You need double the speed and VERY sharp blades.......sharpening blades will need be done like every 20minutes!!!

                • TylerSUPERSAIYANsaitama

                  No one:

                  Literally not a single soul:

                  Ants: AAaAAAaAh!!

                  • franklin castillo
                    franklin castillo  1 weeks back

                    Can you do an episode on how a chainsaw works

                    • TrexHunter40
                      TrexHunter40  1 weeks back

                      7:44 we can distinctly hear the explosions of the motor, woaw!

                    • Corey Sellers
                      Corey Sellers  1 weeks back

                      Pleas do a tune up on youre Huskvarna zero turn. It sounds like its starved for air.

                      • Goose gaming gang
                        Goose gaming gang  2 weeks back

                        The satisfaction

                        • Random Hunter
                          Random Hunter  2 weeks back

                          Why did i click here, as soon as i saw ur face i was like, i cannot be bothered right now, i might have also watched this before

                          • Joseph Horrobin
                            Joseph Horrobin  3 weeks back

                            Any one else not understand

                            • F.B.I
                              F.B.I  3 weeks back

                              *Grass has left the chat*

                              • Michael Drapper
                                Michael Drapper  3 weeks back

                                what about brush cutters and strimmers and flymos

                                • MrPbip
                                  MrPbip  3 weeks back

                                  You need to sharpen your blades terribly dull

                                  • Stxllor
                                    Stxllor  4 weeks back


                                    never be ashamed to learn something new.
                                    be ashamed that you were ashamed that you learnt something new.
                                    after all, you are SmarterEveryDay.

                                    • Chris Henry
                                      Chris Henry  4 weeks back

                                      Can you do a video on weed eaters or weed whackers as known in some parts of the country

                                      • blackbar gaming
                                        blackbar gaming  4 weeks back

                                        For the lawn tool segment. i would like to know how the energy is transferred from the fly wheel to the ram on a kinetic log splitter.

                                        • Sheila olfieWay
                                          Sheila olfieWay  1 months back

                                          take a lawn mower blade or maybe a small version put it into a acrylic box and then run some sort of smoke into the blade to see how the air flows. And don't forget the slow motion camera to really see that airflow

                                          • OFF ROAD
                                            OFF ROAD  1 months back

                                            You are becoming my favourite channel.
                                            You have some clover in your yard.

                                            • matthew wyatt
                                              matthew wyatt  1 months back

                                              What about how a weed eater string gets shortened and new string released at the same time. Centrifugal force and stuff.

                                              • Legendary2442
                                                Legendary2442  1 months back

                                                Can you do a reel mower in slow motion

                                                • mixter7x7
                                                  mixter7x7  1 months back

                                                  you went out in public with that haircut to demonstrate how a lawnmower works ?

                                                  • Maikeru Kurusu
                                                    Maikeru Kurusu  1 months back

                                                    If lawn mowers use vacuum to lift the grass up, how does a sythe (dunno if I spelled it correctly) works? Is it just force that cuts the grass?

                                                    • Robert S
                                                      Robert S  1 months back

                                                      Wow never thought about it that much lol

                                                      • nicolas bourque
                                                        nicolas bourque  1 months back

                                                        have he ever eard about flo-mo mowers ?

                                                        • HotdogAnd aHayride
                                                          HotdogAnd aHayride  1 months back

                                                          Actually the tabs and the air flow they create are for waste management and have nothing to do with how the grass is cut. Speed is what cuts the grass. A blade of grass may not have much inertia but there's enough to keep the grass standing upright as it meets an edge moving at 200 mph. String trimmers don't have aerodynamic surfaces or even an edge, yet they still cut grass due to the speed of the string.

                                                          • nukestrom
                                                            nukestrom  2 months back

                                                            I'm a physicist but I never thought about it before. Nice one.

                                                            • Ashton Raethel
                                                              Ashton Raethel  2 months back

                                                              Would the same effect happen with a whopper snipper?

                                                              • Scootersnmore
                                                                Scootersnmore  2 months back

                                                                cool video grass gets a beating for sure and sharp blade look nice even hair cut LOl

                                                                • Karl Fredrik
                                                                  Karl Fredrik  2 months back

                                                                  it pains me to say thius. but it's not slow enough

                                                                  • Tomar Stevenson
                                                                    Tomar Stevenson  2 months back

                                                                    Nice because my mom 😁 like

                                                                    • Michael Mebane
                                                                      Michael Mebane  2 months back

                                                                      Chainsaw but be safe

                                                                      • eceflyboy
                                                                        eceflyboy  2 months back

                                                                        At time 8:08 Dustin puts his hands where the no-hand hazard label is and reaches for something.

                                                                        • New Zealand
                                                                          New Zealand  2 months back

                                                                          Speed kills

                                                                          • Benjamin Esver
                                                                            Benjamin Esver  2 months back

                                                                            At 0:04 imagine him just running over children with a lawn mower

                                                                            • NMC4114
                                                                              NMC4114  2 months back

                                                                              Look at the Scythe and scything grass.

                                                                              • RCDai
                                                                                RCDai  2 months back

                                                                                What would have been awesome is if you hammered thap tip flap, and tried to use your lawnmower, if it still worked as well

                                                                                • harlaf420
                                                                                  harlaf420  2 months back

                                                                                  Question: i use a Flymo mower (yes i am not american)(we dont have a huge lawn), and flymo mowers dont have any wheels. You move them through the fact that it makes a cushion of air for the mower to "float" on, similar to a hovercraft. Wouldnt that mean that the blade pushes air down (there is an air intake at the top of the mower)? Would it mean that it relies on a cutting technique similar to a sickle/hoe(dont know the word, but the tool farmers used to cut grass like waaaay back)?

                                                                                  Destin the kind of dude that makes people curious about lawn mowers

                                                                                  • AustinAwsome
                                                                                    AustinAwsome  2 months back

                                                                                    This is the most 'dad' video.

                                                                                    • Henrik Strand
                                                                                      Henrik Strand  2 months back

                                                                                      My grandfather own a lawnmower that uses opposing blades.

                                                                                      • Ahmad Zobair Surosh
                                                                                        Ahmad Zobair Surosh  2 months back

                                                                                        I do not understand how does the shape of blade effects the blade to cut the grass?
                                                                                        Can u help me know it better!
                                                                                        I appreciate it

                                                                                        • NobHack
                                                                                          NobHack  2 months back

                                                                                          There is zombie on your lawn

                                                                                          • Fernando Barela
                                                                                            Fernando Barela  2 months back

                                                                                            I wonder if there's a better way? It's just ripping the grass, and I wonder how healthy it really is for it? It just seems to me that the grass goes through too much trauma. Not that it even cares, but, okay...

                                                                                            • Dilu
                                                                                              Dilu  2 months back

                                                                                              This might be a dumb question but here in Argentina lawn mowers don't use blade, they used some kind of plastic string (it's usually green), do you think they would work the same way?