When we did this in highschool our speed/acceleration contest was only over a meter, so I just used the mouse trap to catapult my car over the finish line.

- Dad, why is my sister called Rose? - Because your mother loves flowers. - Oh ok, thanks dad.. - No problem, Mechanical Advantage.

Can you imagine how lucky some future kid is gonna be to be able to call Mark Rober their physics teacher??

It’s almost 2022 and I’m still enjoying this video, I mean the way Mark explains engineering is so amazing.

The internet needs more people like Mark Rober. UKposts should give incentives for NASA employees to become creators.

When mr. Rober is a physics teacher to almost 10 million people and doesn't realize it.

in my 8th grade science class we are actually doing something where you can either build a lander or a rover, no electricity and stuff like that. I had the egg drop thing as an idea for a lander and this for a rover and I'm super excited to test both out and see which one is better.

no one is talking about how mark was outside IN THE RAIN for a bit just so he can explain the topic he was on. I want him to be my teacher.

The way Mark explains physics is not only easier to understand than school ever taught me but he makes it so much more interesting

I wish Mark was my physics teacher...

this has sat in my brain for 3 years and has silently been supporting me through my physics classes. Thank you.

I never did this as a kid but being an auto mechanic now I got a huge kick out of this video! Made me think about the mathematics of transmissions and differential final drive ratios. Super fun keep up the great work!

“Thank yo-“ Niece: ** *Slaps Ice Cream* ** “O WOAAH”

1:36 Mark: But I could lift 10lbs 50 times. *Uses a 12 pound weight*

The way he explained physics is so much better then the 9 years of science class I've taken

I think I just found a lifetime hobby. Every science teacher I’ve ever had said I possess an extremely intuitive understanding of physics and this seems to be a perfect application of that. Just seeing this video makes my mind go crazy thinking of all the ways I could attempt to improve the design. I wonder if you could devise an equation that could predictably determine what the optimal ratio of mechanical advantage for a given car would be, accounting for factors like weight, wheel diameter, coefficient of friction on the wheels, axels, and every other moving part where friction is present. Obviously there’s a perfectly optimal car that could be made if you could fully understand all these factors and that’s what is most alluring to me.

I learned more in the first 5 minutes than a whole semester in high school

Press F to pay respects to icecream

Hey Mark! Nice Video. I wanted to point out that, at 2:03, mechanical advantage doesn't necessarily equal number of pulleys in all pulley systems. This is because fixed pulleys (pulleys which don't move while the load does) have a mechanical advantage of 1, while movable pulleys (pulleys which do move while the load does) have a mechanical advantage of 2. This is why, in your case, the pulley system had a mechanical advantage of 4: the specific arrangement and positioning of 2 movable and 2 fixed pulleys allowed the system to have a mechanical advantage of 4. However, it is important to note that this doesn't happen to all arrangements of 4 pulleys, as if you were to line up 4 fixed pulleys, you would still get an mechanical advantage of 1, not 4. Thus, you cannot say that mechanical advantage equals number of pulleys in all pulley systems. Instead, you could "split" up the tension along the ropes of a pulley through a diagram. Here's the procedure: you first can imagine that you are holding the end of whatever pulley system you are trying to solve with such a force such that the system is in static equilibrium. Next, you can split the tension caused by the force of the load among the ropes of the pulley system. The key to remember is that each unbroken piece of rope will have uniform tension along it. Finally, you keep splitting the tension all the way until you reach the rope which you are holding. The mechanical advantage of the pulley system will simply be the the load force divided by the effort force, which is simply equal to the tension in that rope you are holding, since the system is in static equilibrium. THAT is the correct way to solve for the mechanical advantage of a pulley system (sorry if I explained it badly). Additionally, I wanted to point out that, at 2:08, mechanical advantage of an inclined plane does not equal the ratio of the length to the height unless the inclined plane is just flat and not inclined, in which case I wouldn't really call it an "inclined" plane. But instead, mechanical advantage of an inclined plane is equal to the ratio of the hypotenuse to the height. This can be derived like this: the load force on the inclined plane is simply equal to its downward force caused by gravity, which is simple equal to f = ma = mg. We can split this force into its x- and y- components, which we can then deduce that the force of the load in the direction parallel to and going down the hypotenuse of the inclined plane is equal to mgsin(theta), in which theta is the angle of the elevation of the inclined plane. This means that, if we were to push the load up on the inclined plane with force mgsin(theta), then the system would achieve static equilibrium. In other words, the load would stay in place. Since we know that mechanical advantage is defined as the ratio of the output force to the input force, that would simply mean that the mechanical advantage of the inclined plane would be mg/mgsin(theta), as mg is the output force in this case and mgsin(theta) is the input force in this case. This simplifies to 1/sin(theta). This is simply equal to the ratio of the hypotenuse to the side opposite angle theta, which in this case is height. Thus, mechanical advantage of an inclined plane is equal to the ratio of the hypotenuse to the height.

I laughed so hard when your niece knocked the ice-cream out of your hand.

i was expecting a mouse trap that catches a mouse and drives away with it

I used this video back in seventh grade over the course of 4 weeks to build a fully optimized (realistically) car. Sadly the pandemic hit and I never got to see how far it went.

Wonderful! From your intro, I thought you were going to make your own design, better than any other. Even so, I enjoyed the lesson.

Mark: "A little bit of water spills out every time" Also mark: *Purposely misses cup*

Me: This is boring, I can’t wait till schools out *Schools out* Me:*watches educational videos for fun*

I first did this project in 1987 during my student teaching in Industrial arts. We used two mouse traps which allowed options on how to best utilize them. I continued this project for the next 12 years as an engineering project in Drafting class. Best run was 437 feet in a 12 foot wide hallway so straight tracking was important. The best wheels were 33rpm vinyl record albums. I didn't invent this project and don't know it's origins.

If this is an optimization problem, could you use calculus to find the ideal ratios to reach a certain distance?

Breaking news: Worker in NASA go to school to totally annihilate kids in mousetrap car race

Hey! That's me at 12:50 ! Super cool to see a Science Olympiad event highlighted on your channel! It was great to meet you and talk about my car.

1:43 my guy literally standing in the rain for science.... +1 respect

the longer lever arm also increased the amount of string pulled, and the smaller of the ratio of axle to wheel makes the rotations let the car go further

Mark: “I want to be a physics teacher later on” Every subscribers: ^ *has been learning from him since the beginning* ^ 👀

If he was a teacher at my high school I would never leave the class

In a design class, we had to make a bridge using two pieces of ondulated paper (it had a standard size, but I don't remember anyone) and one roll of masking tape each team. It would be placed linking tow tables 0,5m apart and then we would place 1L bottles over it to see what design would hold more. Many bridges had problems with tortion, or with the paper bending, but my idea avoided those two problems and was able to hold all the bottles available (about 20 bottles) and we started adding other stuff.

I remember doing something like this in school but with bottle cars and their were two types that worked really well because we were going off a ramp aiming to get in a bin, one that worked well was light weight and hand wings to glide in so used hardly any power, the other was heavy and basically dropped in like a rock so used more power (my group was the wings one), their was this one group that tried to just copy both designs and combine them together so the heavy thing combined with the wings, so theirs didn't work well because they tried to combine two completely different methods.

i dont watch because its relevant, i watch because its entertaining...

When you learn more in a 15min video then in 13 years school

This was a fun high school competition back in the day. I still keep my car as a momento as it's just such a satisfying design - the comp was a speed one and we took the win. The car we made was four wheel drive and light - the four wheel drive was chosen to maximise the traction availability along with tricks to manage traction and energy. We had hypothesised about friction and traction in class, none of us had real karting or racing experience at the time but this was certainly a time where it became apparent. The result was fast enough to be challenging to time.

This is a fantastic video, but I will say that in 8th grade my best friend and I were tasked with building a mouse trap car that didn't use a pulley system as a sort of "bonus" project. We built a tiny car, launched it with the mousetrap, and won the competition for our class. It believe it went almost double the next best vehicle's distance, and I personally built the 2nd place car.

Lesson of the day: don't make a bet with mark

If he was my physics teacher I would skip other classes to go to his class

The fact that I saw this video when it came out and just today I was assigned to make a mousetrap car in my high school physics class.

I made a mousetrap car in 10th grade with a gearbox that made it run for over 30 seconds continuously, but the wheels spun on the tile floor it was tested on and barely went anywhere. Needless to say I didn't win but I've never seen anyone else make one like mine.

you would be a GREAT science or tech ed teacher

Nobody: Mark: Dang it I wanted to be a physics teacher but I ended up working at nasa

When I was in HS I built many of them. Our rules wouldn't allow for any modifications to the trap and had overall dimension regulations so it could only be so large. Mine would go the full length of the basketball gym at the school. Great memories. Cool video

WOW so nicely done. Wish I had this when I was teaching mousetrap cars years ago.

Just get an electric mousetrap and use it as a motor *modern problems require modern solutions*

Somebody: Creates a contest that's a thing just in the USA. USA: Yay, World Record! ;-)

Great video, small thing, had this same mouse trap challenge in my junior year in high school physics class in 1989. It was a great learning experience! Don't remember who won, we had an incredible teacher, just like Mr. Karud. Big props to him for his dedication to his students!

I remember making one in highschool when I had terrible time management. I had to reach a certain distance, and all I had was cardboard and 6 hours the day before it was due. I used a thread spool as a front wheel, comically large lever arm, and the largest circle I could cut out in the back. The thing went 5x the distance of almost everyone else, only being beaten out by the super low friction speedster of my buddy. It's a cherished memory of mine.

The ice cream cone slap was the funniest thing I’ve seen in awhile.

Mark: Talks like a smart person Me: I don't know what you're talking about, but it seems interesting

I made one with 2 mouse traps in series with the string attached to a 2 sided fishing hook so it could be tranferred to the second bar. It was a cool idea and worked but not as well as the long armed ones.

진짜 이유투버는 내가믿고 구독하고 보는 유튜버다🎉항상 재미있게 과학을 설명해주셔서감사합니다❤

Can you believe I had to watch my favorite youtuber for homework on my Mouse trap car?? :O

I wish we did something cool like this when I was in school... good job on the video! :)

Hey Mark, Any chance you can make a video on your work bench. I think a lot of people and myself would be interested in it. It’d probably encourage people to recreate and experiment with their own science projects. Best- PS Phat Gus rules.

Mark Rober, im making it, the current best for my school is 33 feet, thanks mark, we will win

13:30 this is how happy I imagine Mark is *ALL THE TIME* when he's learning, making, and teaching! Keep up the great work!

My friend built a mousetrap car and it exploded when he tested it in competition

Built a pinewood derby car a long time ago and my dad gave me some of the graphite he had -- those wheels had NO resistance, nice advantage!

your has a bigger wheel, so a bigger scirconference, so just spin faster if the rotation force is aplied to the center of it and the theet are for more friction

This video is a tutorial for almost all kind of rolling. I mean, it explains drag racing cars tweaks, bicycle gears/wheelsize, etc. Love the video, thx

I remember building one of these in my 8th-grade science class. Once I finished the project, and presented it at school, my father attached Estes Model Rocket Engines to the car.

We use to race RC cars before they came out with li-ion batteries. I generally raced stock that meant 6 cells, no ball bearing motor with less turns. I think we ran either 3 minute heats or 5 and it was a great feeling when you could get your car across the finish line and then the battery run dead on another lap or two. The goal was to use all the stored energy even if it was a crappy battery pack.

Thank you for the video Mark Rober, I'm doing mouse trap racers for an engineering unit!

Jokes on you, I'm part of the 3.3% of people who have a school project on this

"I can lift 10 pounds 50 times" *has a 12 pound weight*

Explained mechanical advantage in five minutes with twenty or so examples better than my physics teacher did for a whole school year . . .

I remember doing this with the short mouse trap lever design and at the competition knowing how much I messed up but me and my group came 4th over all so it was ok

He deserves more. He literally travels soo far for just a video!😸

I remember building mine out of legos. It impressed my Physics Teacher so much that he asked if he could take pictures of it to use for future examples. I hated him as a person, but I respect him as a teacher.

Thanks for the video.. I almost forgot I built one in HS. My wip traveled 114 ft., I'll never forget that.

Bro's filming in rain.. And I didn't notice the first time.. That is dedication! Keep the lessons going! I love your videos!!

I love what you do and patiently wait for each video.Thank you for making me and my family smarter and more interested in science.

al is my current physics teacher, ama.

The satisfaction you get when you learn about the stuff he’s talking about

We were assigned to watch this in our science class today Amazing decision

All I said was "new Mark Rober video" and the 5 yr old and 9 yr old came a-runnin' :) We love science in this house.

I'm never going to let Mark pour me a glass of tea.

should have watched this 2 years ago. We made one in middle school. One of the best ones in my class was actually built from paper! (he used paper tubes and idk about the wheels, its been 2 years after all) mine had a replaceable mouse trap and cd wheels and it did pretty well

Ive done this in 5th grade and it was very fun trying to build one and getting it to go far

The street fighter transition at 4:27 is amazing. Thank you for putting in that extra effort into your videos!

Was in a high school class that did this in the 1990's. The teacher had two criteria, first to 10' and longest distance traveled. So I had a car with a conical spool on the drive axle, which helps with both good starting acceleration and changing the drive ratio to stretch out the range. So I thought I was clever in trying to score well on both criteria. Turns out I wasn't clever enough... Some other kid in the class found a loophole. At the time the contest didn't stipulate that the mousetrap had to be part of the car, nor did it specify that the car must stay on the ground. So he had one of those Micro Machines toy cars and used the mousetrap to catapult it down the hallway. It flew about half the distance before bouncing off some lockers and skidding to the end of the hall. Thus insta-winning both categories, even if it wasn't in a way that was the intended nature of the contest. The teacher allowed that because he considered it fair given the provided rules, but changed the rules for the next class that did this project so no easy cheats could happen. I can only laugh about it though, since I was on friendly terms with the kid that beat my design. Nobody was allowed to copy each other, so I was wondering what strategy he had that would beat mine and I thought he was joking about it. (He wasn't wrong.) So what about my car? It ended up 4th in distance and 2nd on speed. Didn't have access to fancy bearings like others did for the distance, and only got the speed because everyone else trying for it spun their tires on the polished floor. However it did get awarded the most interesting design for having a novel approach compared to others. Everyone else thought the overall win strategy was too cheesy too.

Mark is better at teaching me this than school ever has

Mark, your buddy, Al, in Texas said "I came up with this idea back in 1991", but my high school physics teacher was doing mousetrap cars in the mid 1980's. Some of my classmates were using vinyl 33 1/3 LP records as wheels. (Yes, there was recorded music media long before .mp3 and CDs.)

1:25 Dang, dat gurl is savage.. Edit: OMG Thank you soooo much for all the likes

Mark: Talking about Mechanical advantages Weather: RAIN! Mark: Keeps talking!

I love watching you because you teach me things without making it boring

Such a fun idea for a snow day craft with my science-obsessed kiddo :D

Holy cow! Thank you for another amazing video. I have two sons studying engineering at Utah State and we all love your videos. We're going to have to have a family mousetrap car competition. and then AFTER that, I'll show them the video. Keep up the great work.

"I could move the earth if I had a lever strong and long enough" -Archimedes (supposedly)

Traction and momentum is also important for long distance. At grade 8 my partner and I beat college students for a state record (nothing near the world record) Our rig was more like a dragster and theirs was beautifully designed, large wheels and light weight.

this also works in car engines, if you have a longer piston you will produce a lot of torque and if the piston is short then you would be able to make the engine rpm higher

Can we get a R.I.P in the chat for Mark's ice cream

i just love how she punches the icecream out of marks hand

I think he would is a really cool, chill, inspirational, and wholesome teacher in my opinion. 10/10

Hey Fun fact! Me and my group in a mousetrap car project got first place, thanks to this. It really helps. Thanks a lot for the ideas. Our task was the long distance car and we used the same principle as the world record type. Tip, you really need to calculate the ratio, if it’s to big the car won’t move at all. My group learned that the hard way. And everyone else in our class who tried the same principle gave up, because I would not move.