The Physics of Acceleration: Traction and Braking

When it comes to accelerating a car from 0 to 60 miles per hour, there are several factors at play that can affect its performance. One of the most important considerations is traction, which refers to the ability of the tires to grip the road and transfer power to the wheels. In order to accelerate quickly, a car needs to have sufficient traction to propel it forward.

However, traction also has an effect when braking. When a car brakes, it needs to slow down quickly in order to come to a stop safely. This requires a significant amount of traction to grip the road and transfer power to the wheels in the opposite direction. As such, the tires play a critical role in both accelerating and braking.

The relationship between acceleration and braking is often misunderstood, with many people assuming that it's possible to accelerate as quickly as you can brake. However, this isn't necessarily the case. In fact, when it comes to braking, cars are typically much slower than they are when accelerating. This is because the forces involved in braking are much more extreme than those involved in acceleration.

For example, let's consider a car with a 0-60 time of 2.53 seconds and a 60-to-zero stopping distance of 109 feet. Using the basic physics of motion, we can calculate the average acceleration of this car while it was accelerating from 0 to 60 miles per hour. This comes out to an astonishing 1.08 g-forces, which means that the car was accelerating at approximately 110 mph in just 2.53 seconds.

Similarly, when it came to braking, we can calculate the average deceleration of this car as it slowed down from 60 to 0 miles per hour. This comes out to an impressive 1.10 g-forces, which means that the car was slowing down at a rate of approximately 110 mph in just 109 feet.

It's worth noting that these calculations are based on several assumptions, including the assumption that the tires provide sufficient traction and that the car is accelerating or braking smoothly without any significant losses due to friction or other external factors. However, even when these assumptions hold true, it's clear that acceleration and braking are two very different things.

In fact, while acceleration can be achieved at a relatively high speed, braking is typically much slower. This is because the forces involved in braking are so extreme that they require a significant amount of time to slow down. As such, the tires play a critical role in both accelerating and braking, and their performance can have a significant impact on a car's overall performance.

One interesting consideration when it comes to acceleration is the effect of rear-wheel drive versus all-wheel drive or four-wheel drive cars. In general, rear-wheel drive cars tend to be faster and more agile than all-wheel drive or four-wheel drive cars because they are able to transfer power directly from the engine to the wheels. However, this also means that they can be more prone to losing traction on slippery roads.

On the other hand, all-wheel drive or four-wheel drive cars can provide better traction and stability on slippery roads, but they often come at the cost of reduced acceleration and agility. As such, when it comes to acceleration, rear-wheel drive cars tend to have a significant advantage over their all-wheel drive or four-wheel drive counterparts.

A notable exception to this rule is Tesla's Model S, which boasts an impressive 0-60 time of 2.5 seconds thanks to its advanced electric motor and sophisticated traction control system. However, even in the case of Tesla's flagship model, there's an asterisk next to the 0-60 time - it's not actually possible for a production car to achieve a 0-60 time under two seconds.

To put this into perspective, we can calculate the theoretical 0-60 time of several high-performance cars, including the Porsche 911 GT2 RS. Using data from Motor Trend, we find that the 2018 Porsche 911 GT2 RS boasts an astonishing 87-foot stopping distance, which translates to an average deceleration of 1.38 g-forces and a theoretical 0-60 time of just 1.98 seconds.

This is incredibly fast, and it's worth noting that no production car has ever achieved a 0-60 time under two seconds. While Tesla claims to have done so with the Model S, its asterisk next to the 0-60 time suggests that this may not be entirely legitimate. As such, the Porsche 911 GT2 RS remains one of the fastest production cars in the world, and its impressive acceleration and braking capabilities make it a formidable competitor on the road.

In conclusion, the physics of acceleration and braking are complex and multifaceted, with many factors at play that can affect a car's performance. While acceleration is often faster than braking, there are some notable exceptions - such as Tesla's Model S, which boasts an impressive 0-60 time despite its lack of legitimacy.

"WEBVTTKind: captionsLanguage: enhello everyone and welcome in this video we're going to get unreasonably passionate about pointless statistics so we're talking about how tesla's model s plaid claims a 0 to 60 time of 1.99 seconds but in reality it more than likely doesn't actually have a 0-60 time of under two seconds and tesla's own website suggests this if you do a little digging here's the thing i really really like cool engineering and tesla does a lot of that i also really really don't like deceptive marketing and tesla well i'll let you finish the sentence so here's the problem if you go to tesla's website you'll see three options for the model s the long range with a claimed 0 to 60 of 3.1 seconds note that there is no asterisk next to this claim then the plaid with a 0 to 60 of 1.99 seconds again note that there is no asterisk next to this claim and finally plaid plus with a 0 to 60 of less than 1.99 seconds and again no asterisk next to this claim but what if you read the fine print well that pulls up a page which provides more details and shows you a side-by-side comparison of the different models turns out the 1.99 second claim actually does have an asterisk in the fine print and that asterisk which is a difficult word to say frequently reveals they're subtracting the first foot of rollout i have three problems with this first off most people don't know what rollout is and that's totally fine why should the masses know about some drag racing measurement method used by the national hot rod association or nhra the second problem i think it's quite deceiving how hidden this information is it should be shown on the main purchase page and third i find it a bit odd that they subtract rollout for the more expensive models but as there's no asterisk next to it presumably not the base model that helps differentiate them making the performance gap appear wider than it really is since subtracting a foot of rollout would probably put the base model in the twos all of this is just shady marketing in my opinion so let's talk about rollout theoretical 0-60 times what tesla's actual 0-60 time might be and what today's fastest 0-60 could actually be alright so first a quick recap on rollout so if you head to a drag strip and you've got two cars that are going to race obviously they need to start at the same line right and so what drag strips have are these two light beams going across and you use those beams to line up the cars so first you'll hit a pre-stage beam that lets you know that you're very close to the line you're going to start from and then your tire rolls in front of that stage beam going across and you know hey i'm at the line i'm ready to launch down this drag strip now when they say go you have a little bit of time where your tire is moving forward and it hasn't yet broken that stage being that beam in the front because the tire's moving forward and so it moves forward about a foot before the tire actually leaves that beam and that's when the 0 to 60 clock starts actually ticking we're not talking about reaction time here we're talking about the car's actual 0-60 the timing starts once it breaks that beam which means you get one foot of free acceleration now the reason tesla does this is because this is what all the big auto magazines do and all of them know that this is deceptive the cool thing about the auto magazines versus tesla is that they actually openly admit what's going on behind this one foot so motor trend for example gives you the data of what happens in that one foot so what is the impact of that one foot of roll out and so for example with the tesla model sp-100d that they tested it was able to accelerate to 5.9 miles per hour and that first one foot shaving .26 seconds off its zero to 60 time another example a mclaren p1 was able to accelerate to five miles per hour an event adore something a bit quicker than the tesla in that one foot 6.1 miles per hour and an example like a toyota camry it's able to accelerate to 4.3 miles per hour in that first foot so this is not a 0-60 in the case of the tesla it's more like a 6 to 60 which we can all agree 6 to 60 and 0 to 60 are very different measurements correct i think another way of phrasing this question like if you were to look at a car maker or a car maker told you hey our car can stop from 60 miles per hour down to zero miles per hour and 109 feet that's the number that motor trend got for the tesla model s p 100 d stops from 60 to 0 109 feet and then you're like you know actually that's from 55 miles per hour but we just said 60. you wouldn't be like okay that's fine you know it's they just took off five miles an hour so this the same should be true for the reverse right why are we talking about a 5.9 to 60 mile per hour time meaningless statistic we don't need it throw it out so what is the actual 0-60 if tesla's claiming that with their motor trend spec uh you know removing that first foot of rollout they're able to get 1.99 second zero to 60. well you know best case like this event to door that shaved off 0.2 seconds from its time so let's say something like 0.2 0.2 and suddenly our 0-60 in reality is more like 2.19 seconds now is it possible for the true 0-60 to be under 2 seconds for example looking at that plaid plus it says less than 1.99 seconds so this kind of ambiguous number we don't know what it really is is it possible for that to be under 2 seconds well what i like to do is look at the breaking so the braking can teach us something basically the thought is a car cannot accelerate faster than it can break and i made a video about this about five years ago kind of breaking this down the simple logic is if you take a vehicle's braking distance from 60 miles per hour down to zero you find out what that braking distance is from that number you can determine what its deceleration rate is its average deceleration from 60 to zero that gives you essentially what your peak grip is and if you reverse that and then use that to calculate a acceleration using that g force from 0 to 60 miles per hour that can give you your theoretical limit of what could my 0 to 60 be and the reason being again i don't know of any car out there that can accelerate to 60 miles per hour faster than it can decelerate from 60 miles per hour down to zero it does not happen with road cars so why should you trust that well drag first of all helps reduce a 60 to zero time which means it would hurt your 0-60 time because drag is helping to slow that car down if you let off the gas pedal you just start slowing down aerodynamic drag starts to bring you to a stop and so that is helping reduce your 0 to 60 time that's an advantage you do not have accelerating the effect is small right 60 miles per hour isn't all that fast and not a lot of time is spent close to those speeds while accelerating also downforce can help your sixty to zero now it could also theoretically help your zero to sixty but because the speeds are so low it's not going to be that much downforce really we're just talking about a little bit of added drag which is going to slow your car down not help it speed up on the flip side there are a couple advantages in accelerating versus braking usually cars that are very quick at accelerating have larger rear tires than front tires meaning the bigger tires have more weight on them while accelerating rather than while they're braking so that's an advantage to accelerating also i think it could be made the argument could be made that abs maybe isn't quite as fast to react as the most sophisticated electronic traction control system using an electric motor i think that could go either way but i think in reality you know it could be that an electric motor might be a little bit more sensitive and help provide the exact amount of force needed to not break friction and accelerate as fast as possible and then finally this logic does not apply to rockets right so in the future if they do end up putting a rocket on the back of a car well the traction now is no longer an issue right the rocket is what's pushing it forward not the tires and so you can have a 0 to 60 that is faster than two seconds or whatever the frictional limit of those tires are all right so let's look at a quick example using some data from motor trends so they tested a model s p 100 d they got a true 0 to 60 of 2.53 seconds and a sixty to zero breaking distance of one hundred nine feet using this two point five three seconds we can do the mass say velocity equals acceleration times time and we can do the math to find out that that vehicle on average is accelerating at 1.08 g's now from that breaking distance of 60 down to zero of 109 feet we can do the math and figure out what is the average deceleration there which is 1.1 oh geez and as i mentioned earlier you can't out accelerate uh your braking right so the acceleration g-force is just slightly less uh than the peak braking g-force uh i don't i don't think that is going to be reverse so your theoretical 0-60 in this case looking at the breaking g-force would be 2.48 seconds and the reality was 2.53 seconds so fairly close in predicting you know what's that 0-60 actually going to be and also not breaking a rule of you know decelerating uh quicker than you're accelerating now it's worth mentioning that this p100d was riding on michelin pilot super sport tires and there are better tires available today so that means more traction which means potentially a faster car so i did this little exercise back in 2016 and i said that based on the best stopping distance we saw of any production car which was 90 feet which means a deceleration of 1.34 g's the best 0-60 possible in a production car in the year 2016 would be 2.05 seconds now that was 2016. tires have gotten better since then great so actually if i were to predict today what is the best possible 0 to 60 well a 2018 porsche 911 gt2 rs was able to stop from 60 to zero in just 87 feet you can do the math on that that gives you an average acceleration of 1.38 g's or 44.5 feet per second squared which gives you a theoretical 0 to 60 speed over time of 1.98 seconds which is very cool because that's under two seconds so theoretically it is possible that today i believe a car could possibly hit production car could hit 60 miles per hour in under two seconds which is very cool so no production car has done it right no production car has gotten a 0 to 60 in under 2 seconds so that's why it's this really cool thing right now here's tesla claiming they can do it except there's an asterisk next to it and there shouldn't be an asterisk next to something that's cool it should be genuinely done so to tesla i would say at least you know at the very least put a little asterisk on the main page that says 1.99 uh like you do on the you know behind the scenes look of what the actual speed is or better yet put the actual 0-60 speed on it like you do for the base model or better yet actually get a 0-60 under 2 seconds and then we can all celebrate it could be legitimate from 0 miles per hour to 60 miles per hour how cool would that be thank you all so much for watching if you have any questions or comments feel free to leave them belowhello everyone and welcome in this video we're going to get unreasonably passionate about pointless statistics so we're talking about how tesla's model s plaid claims a 0 to 60 time of 1.99 seconds but in reality it more than likely doesn't actually have a 0-60 time of under two seconds and tesla's own website suggests this if you do a little digging here's the thing i really really like cool engineering and tesla does a lot of that i also really really don't like deceptive marketing and tesla well i'll let you finish the sentence so here's the problem if you go to tesla's website you'll see three options for the model s the long range with a claimed 0 to 60 of 3.1 seconds note that there is no asterisk next to this claim then the plaid with a 0 to 60 of 1.99 seconds again note that there is no asterisk next to this claim and finally plaid plus with a 0 to 60 of less than 1.99 seconds and again no asterisk next to this claim but what if you read the fine print well that pulls up a page which provides more details and shows you a side-by-side comparison of the different models turns out the 1.99 second claim actually does have an asterisk in the fine print and that asterisk which is a difficult word to say frequently reveals they're subtracting the first foot of rollout i have three problems with this first off most people don't know what rollout is and that's totally fine why should the masses know about some drag racing measurement method used by the national hot rod association or nhra the second problem i think it's quite deceiving how hidden this information is it should be shown on the main purchase page and third i find it a bit odd that they subtract rollout for the more expensive models but as there's no asterisk next to it presumably not the base model that helps differentiate them making the performance gap appear wider than it really is since subtracting a foot of rollout would probably put the base model in the twos all of this is just shady marketing in my opinion so let's talk about rollout theoretical 0-60 times what tesla's actual 0-60 time might be and what today's fastest 0-60 could actually be alright so first a quick recap on rollout so if you head to a drag strip and you've got two cars that are going to race obviously they need to start at the same line right and so what drag strips have are these two light beams going across and you use those beams to line up the cars so first you'll hit a pre-stage beam that lets you know that you're very close to the line you're going to start from and then your tire rolls in front of that stage beam going across and you know hey i'm at the line i'm ready to launch down this drag strip now when they say go you have a little bit of time where your tire is moving forward and it hasn't yet broken that stage being that beam in the front because the tire's moving forward and so it moves forward about a foot before the tire actually leaves that beam and that's when the 0 to 60 clock starts actually ticking we're not talking about reaction time here we're talking about the car's actual 0-60 the timing starts once it breaks that beam which means you get one foot of free acceleration now the reason tesla does this is because this is what all the big auto magazines do and all of them know that this is deceptive the cool thing about the auto magazines versus tesla is that they actually openly admit what's going on behind this one foot so motor trend for example gives you the data of what happens in that one foot so what is the impact of that one foot of roll out and so for example with the tesla model sp-100d that they tested it was able to accelerate to 5.9 miles per hour and that first one foot shaving .26 seconds off its zero to 60 time another example a mclaren p1 was able to accelerate to five miles per hour an event adore something a bit quicker than the tesla in that one foot 6.1 miles per hour and an example like a toyota camry it's able to accelerate to 4.3 miles per hour in that first foot so this is not a 0-60 in the case of the tesla it's more like a 6 to 60 which we can all agree 6 to 60 and 0 to 60 are very different measurements correct i think another way of phrasing this question like if you were to look at a car maker or a car maker told you hey our car can stop from 60 miles per hour down to zero miles per hour and 109 feet that's the number that motor trend got for the tesla model s p 100 d stops from 60 to 0 109 feet and then you're like you know actually that's from 55 miles per hour but we just said 60. you wouldn't be like okay that's fine you know it's they just took off five miles an hour so this the same should be true for the reverse right why are we talking about a 5.9 to 60 mile per hour time meaningless statistic we don't need it throw it out so what is the actual 0-60 if tesla's claiming that with their motor trend spec uh you know removing that first foot of rollout they're able to get 1.99 second zero to 60. well you know best case like this event to door that shaved off 0.2 seconds from its time so let's say something like 0.2 0.2 and suddenly our 0-60 in reality is more like 2.19 seconds now is it possible for the true 0-60 to be under 2 seconds for example looking at that plaid plus it says less than 1.99 seconds so this kind of ambiguous number we don't know what it really is is it possible for that to be under 2 seconds well what i like to do is look at the breaking so the braking can teach us something basically the thought is a car cannot accelerate faster than it can break and i made a video about this about five years ago kind of breaking this down the simple logic is if you take a vehicle's braking distance from 60 miles per hour down to zero you find out what that braking distance is from that number you can determine what its deceleration rate is its average deceleration from 60 to zero that gives you essentially what your peak grip is and if you reverse that and then use that to calculate a acceleration using that g force from 0 to 60 miles per hour that can give you your theoretical limit of what could my 0 to 60 be and the reason being again i don't know of any car out there that can accelerate to 60 miles per hour faster than it can decelerate from 60 miles per hour down to zero it does not happen with road cars so why should you trust that well drag first of all helps reduce a 60 to zero time which means it would hurt your 0-60 time because drag is helping to slow that car down if you let off the gas pedal you just start slowing down aerodynamic drag starts to bring you to a stop and so that is helping reduce your 0 to 60 time that's an advantage you do not have accelerating the effect is small right 60 miles per hour isn't all that fast and not a lot of time is spent close to those speeds while accelerating also downforce can help your sixty to zero now it could also theoretically help your zero to sixty but because the speeds are so low it's not going to be that much downforce really we're just talking about a little bit of added drag which is going to slow your car down not help it speed up on the flip side there are a couple advantages in accelerating versus braking usually cars that are very quick at accelerating have larger rear tires than front tires meaning the bigger tires have more weight on them while accelerating rather than while they're braking so that's an advantage to accelerating also i think it could be made the argument could be made that abs maybe isn't quite as fast to react as the most sophisticated electronic traction control system using an electric motor i think that could go either way but i think in reality you know it could be that an electric motor might be a little bit more sensitive and help provide the exact amount of force needed to not break friction and accelerate as fast as possible and then finally this logic does not apply to rockets right so in the future if they do end up putting a rocket on the back of a car well the traction now is no longer an issue right the rocket is what's pushing it forward not the tires and so you can have a 0 to 60 that is faster than two seconds or whatever the frictional limit of those tires are all right so let's look at a quick example using some data from motor trends so they tested a model s p 100 d they got a true 0 to 60 of 2.53 seconds and a sixty to zero breaking distance of one hundred nine feet using this two point five three seconds we can do the mass say velocity equals acceleration times time and we can do the math to find out that that vehicle on average is accelerating at 1.08 g's now from that breaking distance of 60 down to zero of 109 feet we can do the math and figure out what is the average deceleration there which is 1.1 oh geez and as i mentioned earlier you can't out accelerate uh your braking right so the acceleration g-force is just slightly less uh than the peak braking g-force uh i don't i don't think that is going to be reverse so your theoretical 0-60 in this case looking at the breaking g-force would be 2.48 seconds and the reality was 2.53 seconds so fairly close in predicting you know what's that 0-60 actually going to be and also not breaking a rule of you know decelerating uh quicker than you're accelerating now it's worth mentioning that this p100d was riding on michelin pilot super sport tires and there are better tires available today so that means more traction which means potentially a faster car so i did this little exercise back in 2016 and i said that based on the best stopping distance we saw of any production car which was 90 feet which means a deceleration of 1.34 g's the best 0-60 possible in a production car in the year 2016 would be 2.05 seconds now that was 2016. tires have gotten better since then great so actually if i were to predict today what is the best possible 0 to 60 well a 2018 porsche 911 gt2 rs was able to stop from 60 to zero in just 87 feet you can do the math on that that gives you an average acceleration of 1.38 g's or 44.5 feet per second squared which gives you a theoretical 0 to 60 speed over time of 1.98 seconds which is very cool because that's under two seconds so theoretically it is possible that today i believe a car could possibly hit production car could hit 60 miles per hour in under two seconds which is very cool so no production car has done it right no production car has gotten a 0 to 60 in under 2 seconds so that's why it's this really cool thing right now here's tesla claiming they can do it except there's an asterisk next to it and there shouldn't be an asterisk next to something that's cool it should be genuinely done so to tesla i would say at least you know at the very least put a little asterisk on the main page that says 1.99 uh like you do on the you know behind the scenes look of what the actual speed is or better yet put the actual 0-60 speed on it like you do for the base model or better yet actually get a 0-60 under 2 seconds and then we can all celebrate it could be legitimate from 0 miles per hour to 60 miles per hour how cool would that be thank you all so much for watching if you have any questions or comments feel free to leave them below\n"