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.

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

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

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.

I wish Mark was my physics teacher...

Press F to pay respects to icecream

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

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

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

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

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!

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.

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

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

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

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.

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

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

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.

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

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

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.

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

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

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

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.

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

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

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

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

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!

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

you would be a GREAT science or tech ed teacher

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.

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.

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

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

Love your videos and I am making a mouse trap car for mine and I decided to watch your video to get an idea of how to do it

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

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

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.

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.

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

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

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

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

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

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

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

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.

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.

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

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

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

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

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

Mark is better at teaching me this than school ever has

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

al is my current physics teacher, ama.

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

I love how cute the cars are!❤❤

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

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.

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.

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

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!

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.

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

I have no idea what he’s talking about but I just listen

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

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

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

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.

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

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

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.

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!

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.

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

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

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.

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

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.

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

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

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

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 just lovw how mark just continued to explain physics in the rain

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

I look forward to working with you! We’re going to have so much fun!

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.

I watched this video 5 years ago and thought about how fun it would be to make a mousetrap car, and now I'm a highschool junior in an engineering class making one that has to travel at least 60 ft. Ita gonna be fun

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

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

Are all mouse traps created equal? Do you have to compensate for the differences between your mouse trap and the "standard mouse trap" kept at the Institute des Standards Scientifiques in Paris?

I did this like 16 years ago. Tip to anyone reading the comments researching build ideas. Give your spring more tension by putting pennies under the opposite side compressing spring a little bit more.

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