While you may get some movement, the short answer is no.
Actor, athlete, and, self-proclaimed Florida janitor Brian Kahrs made a handful of headlines around the world because of his viral video showing the “part-time” janitor using a mop-bucket on wheels, a leaf blower, and, an umbrella as a “quirky” alternative method of transportation. But is this mode of transportation possible with a cheapo leaf blower, a skateboard, and an umbrella from Walgreens? While technically possible, the short answer is no, you can’t actually use a gas-powered leaf-blower and a mop-bucket to get to work.
Let me explain.
The Janitor in the viral video switches from a mop bucket to an electric skateboard on top of a modified mop bucket to make this possible. You can see the obvious transition from here to here.
First, here’s the viral video below, a fit, disheveled, and quirky janitor gets into a mop bucket, pops open a flimsy umbrella, and uses a $49 leaf blower to push himself all around town. Well, shiver-me-timbers, this man’s created an efficient form of transportation that allows him to travel several miles around town, all using just .1 gallons of gas, the amount a gas-powered leaf blower can hold. All our nation’s fuel issues are solved! Why doesn’t everyone ride around in mob-buckets with umbrellas?
Enter Newton’s third law
Newton’s third law says for every action, there’s an equal and opposite reaction. Say, for example, you removed the umbrella and pointed the leaf blower in the opposite direction of travel. With the leaf blower blowing in the opposite direction, according to Newton’s third law, you’d be constantly be pushing against air and would move forward.
That experiment’s been replicated on Youtube many times. This basic physics explains thrust and is what accelerates jets, fast enough to create lift.
Even in the absence of air, like in space, thrust still works, however, you need a lot of energy and fuel to get going anywhere fast enough. It’s why come space flights slingshot around planets to get a speed boost.
Notice that, without an umbrella, you’re still moving far too slow to be an efficient form of transportation.
Add an umbrella
With an umbrella, Newton’s third law still applies. Let’s think this through.
All an umbrella does is, rather poorly, deflect air exerted against it, making it “reverse” direction, losing thrust energy as it’s pushed against the umbrellas fabrics, bounced back, and deflected in a direction that’s not as linear as the viral janitor’s video would make us believe it does.
This argument has been explained and re-hashed many times thanks to an old vine video that brought up this same argument.
Here’s an explanation by Twitter user @Solar_Huskie copied from this Complex.com article.
Here’s a mirror just in case that tweet disappears.
And, as you would expect, this janitor’s viral video’s been replicated for Youtube, too. Here’s a simple video, followed by a close copy of the mop bucket janitor.
Notice in the above video’s experiment, the 225 MPH leaf blower is much more powerful than the janitor’s, overcomes the cheap umbrella, and barely gets the skateboarder moving.
As the ultimate proof that a leaf blower pointed at an umbrella is a poor method of movement, myth busters did something similar years ago, using a fan boat’s blower pointed at a sail as a means of transportation. With the fanboats powerful engine, they were only able to get to 3 MPH.
Twitter user @PeteFlintMurray sums this janitor’s video up quite nicely.
“It’s a man in a yellow bucket on an electric skateboard, the blower and umbrella are just theatrics.”
What about the reverse thrusters on commercial jet aircraft. Those devices do a fine job of slowing down an aircraft with the help of wheel brakes for the final act of stopping.
True it appears a skateboard is under the mop bucket but I would not expect the casters on a mop bucket to provide a “good” ride. And last, one would expect a method of steering is required no matter what is behind forward motion.
Thrust reversers work because they add significant amount of energy to the air that goes through them. A box fan simply takes air and accelerates it, while it also pushes itself in the other direction. A jet engine adds fuel, and when the fuel ignites and expands with compressed air at 30 atmospheres it produces a lot more energy than what came in from the front side of the engine. The air that hits the thrust reverser panels has a massive amount of exothermic energy from the fuel molecules igniting and breaking down.
A simple fan has no exothermic reaction – so the air that comes out of a fan does not significantly have more energy than the air that comes in it.
Well, everyone who quotes the Newton’s third law which is basically related to momentum conservation, they always forget the important condition. The system has to be a closed system with no exchange of matter. My argument is that air particle flow throw a system and the engine is generating energy. Therefore, technically the momentum of all air particles that enter the system later will leave the system with different momentum. And momentum change translates into the net force. The magnitude of the force is another question.
how about on a bicycle..a blower nozzle pointed back and down towards a wheel with paddles or cups to catch the air so as to blow not only on a paddle wheel essentially but also toward the ground and opposite direction of travel with the nozzle sized reduced to increase speed /pressure and directed at optimal angle and distance from the paddles etc to catch as much as possible.. pushing off the ground some and rearward..the combined methods transferring energy to forward movement should yield much better results I would have to assume.. as it’s not working against itself since all energy is released in proper direction and could even get the air from a front facing intake utilizing suction in a positive direction also.. I think it may work ok with wheels aired up reducing resistance etc and some effort to produce the most effective “paddle” design possibly something of a variable nature as to maybe change nozzle position in relation to speed etc like towards outer wheel diameter for more more to get going and then to tighter diameter of wheel for more speed once rolling etc.. I would like to see it done.. maybe even with a 3wheeled bike.. I put a curve shaft trimmer on a mountain bike friction drive and once going fast enough for the rpms to get up there it pulled me along well.. about as fast as I could peddle in top gear trying to match the speed or assist…and that is much less power than the blowers out there ..