Newton's 3rd Law Explained with Skateboard, Rocket

Using a skateboard and a makeshift rocket, USC Dornsife physics professor Nick Warner demonstrates Newton's Third Law to his students.
The USC Dornsife College of Letters, Arts and Sciences is the academic core of the University of Southern California in the heart of Los Angeles. Learn more at www.dornsife.usc.edu
Learn more about the USC Dornsife Department of Physics and Astronomy: dornsife.usc.edu/physics/
Video by Mira Zimet P.A. Angelica Zatarain

[@ChipzyWrathful]

That man really knows how to teach, congratulations to him

[@kevinhuang7493]

Of all of the non-major classes I took, this was my favorite. Great teacher, super enthusiastic about the material, and very knowledgeable. This class was a General Education class, so the class was meant for non-majors and people to just get acquainted with the material. Congrats to Mr. Warner, he was just granted a fellowship at USC

[@yuj8914]

what a teacher. Students will want to study more with teachers like him!

[@Arcanum103]

Now that's a nice way of teaching :-)

[@krazykabel]

why cant we have more teacher like this!!!

[@rishijai]

Because its a lot of work

[@GetH0NEY]

Awesome professor!

[@leetoTCG]

If I recall this is from a 100-level general education class so it might be a review lecture. Consequently it's also geared towards students that had no experience with physics in high school which is a likely scenario in many school systems/districts that have you specialize in a science early on.

[@TheXxhairydogxx]

i can't wait til college :D

[@Lastplanet115]

i watched this in my class a few weeks back. pretty cool even though im awful at science.

[@sarahrose4179]

great video

[@terryken18]

why are they learning the principle of newton's third law in college? or are they taking a minor or something?

[@avatarcollides2day]

Love his accent

[@varunsharma-varun]

yes. magnitude of force will remain same but it will be in the opposite direction. if your mass is double of that of the body, you will move with half of the speed of the body.

[@tylorellard2200]

I'm fairly certain as all can agree here this was not a 400 level class, it doesn't matter, everyone starts somewhere...Besides we all came for the fire extinguisher anyways.

[@petermoatamed5474]

I want to know if i push a mass on a smooth surface with force F is there a reaction force acted on me?

[@wintanawelday3228]

Great Teacher! Did anyone else hear the music in the background playing?

[@M3T4LLik4]

+Wintana Welday I realize you are kidding. This guy is almost as bad as watching paint dry haha He leaves no time for students to answer his questions.

[@duneslinetours]

Regards from the Sahara desert of Morocco our teacher. Said

[@jqs1943]

Issac Newtons theory that every massive particle in the universe attracts every other massive particle with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance is absurd The only interplanetary forces that act as an intricate influence between the worlds is the X-gravity field factor of a gravitational force field. X-gravity and gravity are sub fields of a gravitational force field that opperate in opposite directions.

[@blaziustheblaze9935]

So what happens when I fart? Why isn't my body propelled across the room?

[@alwaysoutoftime1518]

+Wesley Norris because science says no

[@alwaysoutoftime1518]

+Ezra Panneck lol

[@M3T4LLik4]

+Wesley Norris: the force of your fart is equal and opposite as your body pushing the fart out. Since the mass of your fart isn't very much, especially in comparison to your body, your body experiences nearly zero acceleration (A teensy tiny amount of acceleration!). Even in a zero gravity setting, your fart might not cause a noticeable acceleration. This is why is requires so much fuel in rockets to take a few hundred kg of astronauts and equipment into space.

[@sfcs3743]

You will --- in space. Excellent way to return to your hatch in space actually, after you run out of propellants and your life line is cut hehe (Gravity). Not in the sense of a joke but, taking a dump might actually give you a practical velocity. The dude who died might've lived....

[@ehabcharek]

I already learned it in high school :P but it's fun to see it explained exactly the same to collage students C:

[@ScoutSniper3124]

It's actually the differential in pressure and resistance (opposing force) between the side of the pressure vessel (balloon) that is walled and the side that is open that imparts motion on a venting balloon. This is proven by the fact a balloon will be in motion while venting even if there is no external atmosphere to impart force upon, such as in a vacuum or outer space. (for a practical example see the Apollo 13 incident, where a pressurized oxygen vessel was breached, the gases vented into the void of space with enough force to throw the spacecrafts (LEM and Capsule) into a corkscrew motion. They covered it well in the movie "Apollo 13" when they mentioned the venting was causing them to be near "gimbal lock" (violent motions in danger of negatively affecting the interaction of the 3 gimbals contained in the INS Internal Navigation System). SCIENCE BITCHES!!!!

[@nineeleven9455]

The professor in this video is spewing pseudo science. Put the balloon in a vacuum and it won’t accelerate. The air will just escape. In the video at the bottom of this link plus.google.com/116502556172406985386/posts/JN6vYXN33ZA watch the experiment on the right, and you will see the balloon has no thrust.

[@my3dviews]

+Nine Eleven The air would escape and move in the direction of the opening right? Which means that the expanding air is pushing on the balloon, so the balloon would move in the opposite direction that the air moves, since the air has mass. There is always a reaction force to any force. You can't have the air move while the balloon remains stationary. As for your link, it is dead. If it is the video with a vacuum creating suction, then that is not what happens in space (vacuum), since there is no suction pulling back on the balloon, but zero pressure in every direction outside the balloon.

[@mirajhonsan8602]

well he must be going over the baiscs i think

[@meSsi2y]

i learned this when i was 5, how old are these people

[@rishijai]

The professor sounds tired from all of the antics of trying to impress kids with short attention spans

[@suavegrips3184]

Kids? They're college students AKA high school graduates AKA older than 17

[@AmericanFightingMan]

what he taught was the superficial stuff.