Suppose you’re going 70 mph on a highway, and a guy in the lane next to you reaches 100 mph, and just as you’re neck and neck you both spot a tree across the road.
Your cars are the same weight, length, on the same pavement (there are no tricks or hidden or unspoken intangibles, it’s a math question) and you both brake the exact same time. Your car stops with not an inch to spare, not touching the tree at all.
Does the other car hit the tree? And at what speed does he hit it?
(Forget about implied momentum if he’s accelerating, etc. For this equation he is going 100 and you’re going 70 when you both hit the brakes.)
The answer might surprise you.
Didn’t watch the video but yes, he hits the tree and my guess is he’s still hauling ass when he does.
8 minutes to explain a math problem is NOT going to get a lot of views…. mine included because I can think of so MANY more useful things to do with that 8 minutes!
71.5 mph.
Use the same deceleration factor for each vehicle; distance to stop from 70 mph is 204 feet, and from 100 mph the distance is 416 feet. Since the slower car stopped just in time, the question becomes one of the speed of the faster car at 204 feet into the deceleration (they brake at the same time): 71.5 mph when he impacts the tree.
Yeah, you can use KE but try explaining that to a jury…
Energy = mass x. (Velocity x Velocity)
Square root of 10,000-4,900
About 71 mph
.5 x mass x (velocity x velocity)
But since both cars have equal mass it did not effect the result. Took me about ten seconds to do the calc in my head
We have the smartest readers too.
IH8 math
What kind of tires? Does the driver know Hillary?
According to Einstein, all motion is relative. So the real question here is, how fast does the tree hit the car?
😉
That was fascinating. But then I’m a math geek.
I was so confused I had a piece of pi and ice cream to calm myself
Luckily for both drivers of the path to the tree the distance to the tree, let’s say 100 feet is first divided in half 50 feet then divided in half again 25 feet, and again 12.5 ft, in an infinite series of divisions by 2 and thus neither car hits the tree.
Male or female drivers?
If female, good looking?
Whaaaaaaaaaaaaat?
If a frog is crossing the same road at 1/2 mph and a train is headed west toward Topeka at 65 mph and one is headed east toward Muncie at 44.5 mph what time is dinner?
Dinner is when the frog is fully cooked.
But, did anyone hear the tree fall?
If an electric train is going west and the wind is blowing east in which direction is the engine smoke blowing?
I enjoyed that, and learned something, too. I liked math when I was in school (oh, so many, many years ago), but have had little need for remembering equations, etc. in my life or career. Still, I am fascinated by the beauty and precision of how our world works.
Heh…Sleipnir, “Worlds Smartest Horse.”
“There are many ways to solve this and um, maybe if you solved it one way, try it another way.”
Right-o!
That was fun. I hate math, but that cutie was entertaining.
But he never answered the question I had. The blue car stoped just in time but the red car smashed into the tree. What happened to the tree after getting slammed into? The end by the blue car should have moved in the opposite direction of the impact at the other end by the red car; thereby smashing into the blue car.
Porch monkey math.
https://www.youtube.com/watch?v=tOFJpsDmKvU